ACETATE SILK 
AND ITS DYES 
MULLIN 


© Raymond Pettibon 


RESEARCH LIBRARY 
eee 1) RESEARCH INSTITUTE 


JOHN MOORE ANDREAS COLOR CHEMISTRY LIBRARY FOUNDATION 


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BY 


CHAS. E. MULLIN, M.Sc. 


Consulting Chemist 


Fellow American Institute of Chemists, Member American Chemical Society, 
Society of Chemical Industry (Eng.), American Association of Textile 
Chemists and Colorist, Society of Dyers and Colourist (Eng.), 
Textile Institute (Eng.), American Pharmaceutical 
Association, and the Society of American 
Bacteriologists. 


WITH A FOREWORD 


BY 
LOUIS A. OLNEY, D.Sc. 


Professor of Chemistry and Dyeing, Lowell Textile School, Editor 
“American Dyestuff Reporter,’ Assistant Editor “Chemical 
Abstracts,’ President American Association of Textile 
Chemists and Colorists, ete. 


NEW YORK 
D. VAN NOSTRAND COMPANY, Inc. 
8 WARREN STREET 
1927 


D. VAN NOSTRAND C 


All rights reserved, including that 


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PREFACE 


In view of the constantly increasing volume of technical litera- 
ture upon all branches of industry, it hardly appears necessary 
to find an excuse for a book upon a subject of such wide interest 
-as acetate silk, upon which there has been no previous specific 
treatise. The present volume is largely, but not entirely, based 
upon two series of articles, “Dyeing Acetate Silk” and “Acetate 
Silk, Its Dyes And Their Application,” originally written espe- 
cially for, and published in, the American Dyestuff Reporter of 
1925 and 1926. 

Some additional papers under various titles were-later published 
in the Textile Colorist and the Canadian Colorist and Textile 
Processor. The information presented in these papers was col- 
lected from every available source, and very little of it was original. 
In the present volume this material has been rewritten, revised, 
corrected, and enlarged to include all information available at the 
time of completing the manuscript. 

The author has no hope that all who peruse this volume will at 
once be able to obtain all of the desired results on the various 
forms of acetate silk, and has merely endeavored to bring the 
available and rather widely scattered information on this subject 
into a concise and convenient form for the busy chemist, dyer, 
and textile technologist. Dyeing is not learned from books alone, 
but it is hoped that the present volume may aid the busy mill man 
to make such experiments as will enable him to solve his own prob- 
lems on dyeing acetate silk. After all, the really successful dyer 
is the man who can take an idea, work it out, and apply it to his 
own problems. 


Acknowledgment 


The author wishes to thank and acknowledge his indebtedness 
to all those who have made this book possible by assisting in any 
way in its preparation or in the collection of the information con- 
tained herein. He is especially indebted to Mr. H. S. Mork, vice- 


3 


4 RETA Teale 


president of the Lustron Company of Boston, Mass., who very 
kindly consented to review the entire manuscript. Mr. Mork 
was co-inventor of the first patented process for the manufacture 
of acetate silk and himself developed many of the manufacturing, 
early dyeing, and other processes used in connection with this fiber. 
He has been connected with this industry longer than any other 
one man and is a leading authority on both acetate silk and the 
methods of handling it. His suggestions, corrections, and infor- 
mation have been most valuable in finishing up the manuscript. 

Among the many Sete who deserve special credit and thanks 
are: 

Dr. Louis A. Olney, Professor of Chemistry and Dyeing at 
Lowell Textile School, who, as Editor of the American Dyestuff 
Reporter, edited all of the original papers by the author on acetate 
silk, and who in this work, as in all other, has been most kind and 
considerate with his help and encouragement. 

Prof. Elmer C. Bertolet, Professor of Chemistry and Dyeing at 
Philadelphia Textile School, who, as teacher and friend has always 
been most willing and able to assist with information on all sub- 
jects. 

The Société pour la Fabrication de la Soie “Rhodiaseta” of St. 
Fons, France, who though located so far away, has made every 
effort to assist with reliable information regarding their products. 

For permission to use the photomicrographs (except Figure 
No. VI) accompanying Chapter No. IV, the author is indebted 
to: The Associated Knit Underwear Manufacturers of America, 
Mr. Roy A. Cheney, Secretary; Mr. Charles H. Hamlin, Re- 
search Associate; and Mr. E. M. Schefike, Research Associate of 
the National Association of Hosiery and Knit Underwear Manu- 
facturers of America. 

Mr. Robert G. Dort of the American Cellulose and Chemical 
Company of New York City. 

Mr. George H. Alpers of the General Dyestuffs Corporation, 
New York City. 

Mr. H. R. Davies of the Dyestuffs Corporation of America, 
Boston, Mass. 


PREACH 5 


Mr. L. J. Hooley of Scottish Dyes, Ltd., Grangemouth, Eng- 
land. 

Mr. Elvin H. Killheffer, vice-president of the Newport Chemi- 
cal Works, Passaic, N. J.; and Mr. P. H. Stott, Chief Chemist. 

Dr. R. E. Rose, Director of the Technical Laboratory of E. I. 
_ duPont de Nemours and Company, Wilmington, Del. 
_ Mr. C. W. Mahnken and Mr. D. P. Knowland of the Geigy 
Company, New York City. 

Mr. W. E. Mitchell of the Ciba Company, New York City. 

Mr. Ernest A. F. Zillessen of the Liberty By-Products Co., 
Belleville, N. J. ‘ 

Mr. F. P. Summers of the Noil Chemical and Color Works, 
New York City. 

Also Mr. B. K: Archer, Mr. H. J. Bogan, Mr. H. E. Hager, 
Mr. H. W. Mertin, and Mr. M. R. Moffatt, all now of the Gen- 
eral Dyestuffs Corporation. 


Chas. E. Mullin. 
3820 Sansom St., 
Philadelphia, Pa. 
June, 1927. 


CONTENTS 
CHAPTER 


IntropucTION By Dr. Louis A. OLNEY 22...) eee BP SRO. 8 


I GENERAL CONSIDERATIONS —. 2... 0 1c ee 
The Rayons in General and Acetate Silk in Particular. 
Rayon Production and Consumption. 


II Tue DEVELOPMENT OF THE RAYONS oe eee ; 
Review of the Advancements and Developments in Manu- 
facture. Early Research and Patents on Cellulose Acetate. 


III PREPARATION OF CELLULOSE ACETATE AND ACETATE SILK 
The Acetylation of Cellulose. “Catalysts.” “Ripening.” Sta- 
bility and Solubility of the Acetate. Manufacture of White 

and Colored Acetate Silk and Mixed Ester Fibers. 


IV GENERAL PROPERTIES OF ACETATE SILK, OTHER RAyons, 


AND NATURAL FIBERS ..... ewerery 

Resistance to Water, Acids, Alkalies, Temperature, and 
Micro-Organisms. Regain, Strength, and Elasticity. Electri- 
cal. Properties, Flammability, Luster, Specific Gravity, Re- 
fractive Index, Structure, and Photomicrographs. 


V IDENTIFICATION OF THE VARIOUS RAYONS)>. Vice eee 
The Various Properties and Tests Used in the Identification 
of the Different Rayons. Bibliography. 


VI. DeEtTecrion or MeErcERIZED COTTON ons one 
Detection of Cotton which has Received the Mercerization 
Treatment and the Estimation of the Extent of this Treat- 
ment. 


VII Dyeinc tHe Orper RAYONS |...) ee 
The General Dyeing Properties of Nitro, "Viscose, and. Cup- 
rammonium Silks. 


VITI Dyerrnce Proprertirs of ACETATE SILK 225.2 eee 
The General Dyeing Properties of Acetate Silk and the Hy- 
potheses Advanced to Explain the Phenomenon. History of 
Acetate Silk Dyeing. The Solution, Colloidal, Mechanical, 
and Chemical Theories. Surface Fixation of Dyestuffs. ‘“‘As- 
sistants’” in Dyeing. The Dye in the Fiber. Basic Dyes and 
Bases on Acetate Silk. Mordanting. Direct Cotton Dyes. 
Acid and Mordant Dyes. Developed Colors. Vat and Sul- 
fur Dyes. Saponification. Phototropism. 


IX Desizinc, ScourInGc, BLEACHING AND TINTING =. eee 
The Methods and Formulas Used in Desizing, Scouring, 
Bleaching, and Bluing Acetate Silk. Scouring and Bleach- 
ing Unions. Antichlor Treatment. Peroxide and Perman- 
ganate. Hypochlorite. Degumming True Silk in the Pres- 

ence of Acetate Silk. 


X Bastc Dyes on*AcETATE SILK ..... 5 ube 

The Methods of Applying the Basic and Gallocyanine Dyes 

to Acetate Silk. ‘“‘Assistants’? such’as Celloxan and Acetane. 

Acetonol N. Topping with Basic Dves. Ammonium Thio- 

cyanate in Dyeing. Increasing the Fastness of the Basic 
Colors. Patents on “Assistants.” 


XI Dyetmne spy PRECIPITATION ......... 000 eee 

The Application of the Basic and Other Dyes by Precipita- 

tion Methods. Patents Covering this Process. Setacyl and 
Setacyl Brilliant Dyes. 


XII. Morpantine ACETATE SILK ..... 2.90) Ree 
. Mordanting with Tin, Aluminum, Chromium, Tron, “ete. 
Thiocyanates and Other Organic Salts in Mordanting. Mor- 

danting Patents. 


XIII Acrp anp Morpant Dyes on ACETATE SIDK9Ql eee 
Use and Application to Acetate Silk. Azo Dyes. The Sul- 
fonic, Carboxyl, Nitro, Arsinic, and Stibinic Groups in Dye- 
stuffs. Setacyl Direct Dyes. Cellit Fast Dyes. Cellutyl 
Dyes. Acetate (brand) Dyes. 


6 


PAGE 


43 


71 


91 


98 


104 


126 


137 


156 


163 


166 


CON TENTS 


CHAPTER 


Pee AGINOAND MORDANT DvE PATENTS ....-2.00sec00000000% 
The Patents Covering the Preparation and Application of Dyes 
of the Acid and Mordant Type to Acetate Silk. Sulfato Dyes. 


XV _ Drrect Corton, SULFUR, AND Vat Dyes oN ACETATE 


eS Foie Sig oe ee D sey Meena dene ates 

The Direct Cotton Dyes and Their Application to Acetate 
Silk. The Application of the Sulfur Dyes to Acetate Silk 
Materials. The Vat Dyes on Acetate Silk. The Ciba Vat 
Dyes. Patents. 


XVI DEVELOPED or Azoic CoLtors ON ACETATE SILK ....... : 
Theory. Components Used and the Methods of Application. 
Oxidized Blacks. Fast Bases. Naphthols AS. Rapid Fast 
Dyes. Fast Salts. Patents. 


XVII SpectaL COMPONENTS FOR THE DEVELOPED COLORS ON 


RR eM ELM as8 2's gs sik KC lane oe a he oa vb ee wee 

The Acedronoles, Acetylines, Azoniles, Azonines, Azoics, 
Azoles, Silkons, and Other Special Azoic Color Components. 
Diazotization and Development on the Fiber. 


XVIII Swetirnc AGENTS or SoLvENTS IN DyEING ACETATE 


RN rot oe we Wa ce vee es Fie ve eldeecavae cae 
The Use of Cet ants or Swelling Agents in the Dye Bath. 
Patents. 


XIX Dyerne Acetate SILK BY SAPONIFICATION ........ 
The Saponification Process and Patents. Advantages ‘and 
Disadvantages. Methods and Formulas. Analysis of Saponi- 
fied Acetate Silk. Dyeing Saponified Acetate Silk. 


RMSEIEIONAMINES . 60. cbc eect cecectecctesdvecscsces 
Development of the First Special Dyes for Acetate Silk. 

Their Application to, and Pronerties on, Acetate Silk.” Pat- 

ents Covering the Ionamines. Direct and Developed Ionamines. 


Pee SE IISPERSOL, TYPE OF DYES 0.0 .c.cccee ers eesccacs 
The Development of Dispersol Type of Dyes or Dyeing by 
Colloidal Solubilization of the Dyestuff. The Development 
and Application of the S.R.A. Dyes. Properties of the S.R.A. 
Colors. Dyeing and Color Formulas. Dispersing Agents. Top- 
ping the S.R.A. Colors. 


XXII Tue Ceratene, Duranot, DispersoL (BRAND), AZONINE 
Direct, CIBACETE, CELANTHRENE, CELLACETE, AND 


OTHER DispersoL Type Dyers For ACETATE SILK ..... 

Their Application to Acetate Silk. The ‘Extra Pastes for 
Acetate Silk.”” Newport Dyes. Properties of the Colors on 
Acetate Silk. Increasing the Light Fastness of Colors on 
Acetate Silk. 


Poe ee isPeRsoL LYPE DYESTUFF PATENTS .....5..500+00000% 
The Patents Covering the Preparation and Application of 
the Dispersol Type Dyes to Acetate Silk. The Dispersol 
Dyes on Other Fibers. Dispersing Agents. Dispersol Type 
Dyestuff Components. Immunized Cotton. 


Doty ee PRINTS AND DISCHARGES ON ACETATE SILK ............ 
Printing Acetate Silk and Unions Containing This Fiber. 
White and Colored Discharges. Methods, Formulas, and Dyes 
Used. Basic Dyes. Acid and Mordant Dyes. Direct Cotton 
Dyes. Sulfur and Vat Dyes. Ionamine Prints. Dispersol 
Type Color Prints. Discharge Pastes. Special Printed Ef- 
fects. Patents. 


PL IVEING UNION MATERIALS ,00.0.%5 cc eee cdg eueneeees 
Dyeing Union Materials Containing Acetate Silk and Other 
Fibers. Acetate Silk White and Colored Effects. Protecting 

Acetate Silk in Boiling Solutions. 


weer asic Dyes on ACETATE SILK UNIONS .>.....0-c0-000> 
The Methods of Dyeing Combinations of Acetate Silk with 
Cotton, Wool, or True Silk with Basic Dyes. Three-Color 

Effects. After-Treating Lustron. 


213 


231 


251 


254 


264 


278 


298 


312 


Co7 


347 


393 


CHAPTER 


XXVII 


XXVIII 


XXIX 


XXX 


XXXI 
XXXII 


XXXII 


XXXIV 


XXXV 


XXXVI 


XXXVII 


XXXVIII 


ACH TAC ere. 


Acip AND MorDAnt Type Dyes on ACETATE S1LK-Cor- 


TON UNIONS. o.¢ scs.0'5 mena eis ble, 010 aie tn 
The Application and Properties of the Acid and Mordant 
Type of Dyes on Cotton-Acetate Silk Unions. 


SuLFuR Dyes oN ACETATE SILK-CoTTon UNIONS ...... 
The Application and Properties of the Sulfur Dyes on Cot- 
ton-Acetate Silk Unions. Patents. 


Vat Dyes on ACETATE SILK-CoTTON UNIONS ....... 
The Application of the Vat Dyes to the Cotton of Acetate 
Silk-Cotton Unions. Caledon Vat Dyes. Anthrene and Thi- 
anthrene Dyes. The Sodium-Phenolate Method. Color For- 
mulas. Soluble Vat Dyes. 


DEVELOPED CoLors ON ACETATE SILK UNIONS .... 
The Application and Properties of the Developed Colors. on 
Acetate Silk Unions. 


Tue IONAMINES ON ACETATE SILK-Cotton UNIONS 
Application and Properties. 


DispErRsoL Tyre Dyers on ACETATE SILK- Corron UNIONS 
Application and Properties of the Various Brands of Dis- 
persol Type Dyestuffs. Solid Colors. Solid Blacks. Two- 
Laine Effects. Hosiery and Knit Goods Unions. Color For- 
mulas. 


Direct Cotron Dyes wuicH LEerAvE ACETATE SILK 
WHITE vec ieee ao cueua tn ce sneer ten 
The Staining Properties, as Regards Acetate Silt, of the 


Various Direct Cotton Dyes. Their Application to Leave 
Acetate Silk White. 


DyEInGc ACETATE SILK AND WOOL oR TRUE SILK ComBiI- 
NATIONS = ccs oe 06 0le-5 @ b alerale oneness: nteltiemee taiant tae=ta==ma aman 
The Dyes Used and Their Methods of Application. The 
Acid and Mordant Type of Dves. Setacyl Direct. Cellutyl 
and Cellit Dyes. Ionamines. Dispersol Type Dyes. One- and 
Two-Bath Dyeing Processes. Solid Blacks. Color Formulas 
and Dyes Used. Staining Properties of Various Dyes. Top- 
ping. Kaline Dyes. Gyco Neutral Dyes. Neolan Dyes. Three 
and Four Fiber Combinations. Katanol in Union Dyeing. 


CLEARING ACETATE SILK UNIONS AND STRIPPING ACETATE 


NS) 5 Fy, OS 
Clearing the Cotton and Acetate Silk in “Dyed Unions. 
Stripping Acetate Silk for Re-Dyeing. 


Mone or APPLICATION ....:.. seen nnn : 
Dyeing Machines and other: Apparatus Used in Dyeing Ace- 
tate Silk in Various Forms. 


DyEING TROUBLES AND FAULTS ..\9e nena 
Difficulties Encountered and Their Remedies, Hydrolyzed 
Fiber. Humidity Conditions. Handling. Unions. Compound 
Shades. Toning or Shading. Leveling and Penetration. Riv- 
ering or Veining. 


SIZING AND FINISHING ACETATE SILK sey -euee eee 
The Materials and Formulas Used in Sizing ‘the Rayons. 
Grading Sized Yarns. Size Requirements. Patents on Siz- 
ing Mixtures. Finishing Materials and Methods. Metallic 
Effects. Soft Finish. Olive Oil Emulsion. Scrooping. De- 
lustered Finish. Egg-Shell Finish. ‘Cire’? Finish. ‘“Hard- 
Candy’? Finish. Delustering Processes. Embossed Effects. 
Mechanical Effects. Finishing Patents. Relustering Celanese. 
Glazed Celanese. Relustering Patents. Washing and Dry 
Cleaning Acetate Silk and Materials Containing It. 


INDEX OF PATENTS BY NUMBERS 4.)...0..-. 5. bet Re 


PAGE 


358 
361 


364 


375 


378 
379 


392 


404 


423 
426 - 


428 


432 


INTRODUCTION 
By Dr. Louis A. Olney 


Professor of Chemistry and Dyeing, Lowell Textile School; 
Directing Editor, American Dyestuff Reporter 


LusTER as a desirable quality of textile materials has been 
prominently before the purchasing public for several thousand 
years. During most of this period dependence has been placed 
upon natural silk for the purpose of producing it, but the past 
half century has witnessed an interesting, and we might say, revo- 
lutionary encroachment upon the domain of the silk worm. 

The luster produced upon cotton yarn and cloth by subjecting it, 
under tension, to the action of concentrated caustic soda solution 
(mercerization) has been and is still a very important factor ‘in 
the production of beautiful textile materials, but the luster pro- 
duced in this manner has not been nearly as great or its develop- 
ment and use so spectacular as that of the so-called artificial silks, 
which in many instances far exceed in luster the natural silks. 

These extremely lustrous fibers have all been produced in a 
manner which imitates the silk worm, as far as mechanism of 
process is concerned, but chemically they are entirely different ; 
and the final fiber substance is not at all comparable with true silk 
in composition. For this latter reason they are not, strictly speak- 
ing, artificial silks. As a consequence of this misnomer, various 
attempts have been made to devise a generic name which would 
not convey an erroneous idea, but which could properly be used 
to designate any type of fiber produced by forcing a semi-liquid 
substance through a very fine orifice, with subsequent hardening. 
Among the names suggested, that of “Rayon” appears to have 
met with the greatest favor, and at the present time it is being 
quite generally used by both textile manufacturer and consumer. 

From a chemical point of view the artificial silks or rayons may 
be classified into two distinct groups: those which are in reality 
regenerated celluloses, and those in which the final fiber substance 
is a cellulose ester. The former group is typified by the Nitro, 


9 


10 AGI RATE io Lies 


Cupro Ammonium and Viscose Silks, while the latter, up to the 
present time, is represented only by the Cellulose Acetate Silks. 
The manufacturers and distributors of the acetate silks have been 
somewhat loath to adopt the term “Rayon” since their product is 
in some respects so different from the regenerated celluloses. This 
in a way is unfortunate since, to some extent, it defeats the honest 
endeavor that has been made to secure a simple word which could 
be used to designate any fiber produced -by the above mentioned 
mechanical process, regardless of the chemical reactions involved. 
Repudiation of the term “Rayon,” however, does not change the 
fundamental situation, and cellulose acetate products still remain, 
as much as ever, in the category of “Artificial Silks.” 

The extensive commercial use of the acetate silks was somewhat 
delayed, owing to the difficulties at first experienced in producing 
upon them full dyeings and fast colors. Failures in this respect 
were simply the natural consequence of attempts made to apply 
to these acetate silks the same dyes by the same methods as had 
formerly been found so satisfactory with the regenerated cellulose 
silks which were so readily dyed by practically all of the methods 
used for the dyeing of cotton. It was not until the marked dif- 
ference between the dyeing properties of cellulose acetate and 
cotton were fully appreciated, and dye chemists recognized the 
fact that entirely’ new dyes and dyeing processes might have to be 
devised, that any great headway was made toward the satisfactory | 
dyeing of acetate silk. The last five years have witnessed remark- 
able developments in this respect, and many dyes of entirely new 
molecular structure, as well as new processes of application, have 
been devised to overcome obstacles which at one time threatened 
disaster to the future of the acetate silk industry. It is doubtful” 
if any of the many remarkable developments which have been 
made in connection with color chemistry and dyestuff application 
illustrate more vividly the ability of the textile and color chemist 
to contend with the most puzzling of problems, when the exigency 
arises. 

Notwithstanding the remarkable developments that have been 
made in the dyeing of acetate silk, there is still much work to be 
done in order that the dyer may be able to color this fiber with the 


INTRODUCTION 11 


same ease, flexibility, and wide range of colors that may so easily 
be applied to cotton. 

In this volume, Mr. Mullin has presented in a comprehensive 
manner the history of the remarkable development of acetate silk 
dyeing and has described with detail the processes which are now 
in use for this purpose. 

- While much of the material presented in this volume is neces- 
sarily a record of the work of other investigators, the author has 
frequently introduced to advantage the results of his own investi- 
gation and specialized knowledge. Being a thoroughly trained 
textile chemist, familiar with the underlying principles of the 
subject at hand, he has avoided the vaguesness of expression and 
technical ambiguities which often appear in books of this character. 

To all those who are interested in the dyeing of cellulose acetate 
silk, this book not only will be found valuable as a reference book, 
but also will serve as a textbook for those who wish to make a 
comprehensive study of the subject. 


CHAPTER I 
GENERAL CONSIDERATIONS 


ACETATE SILK, the infant prodigy of the textile industry, by 
reason of its new, valuable, and extremely interesting chemical, 
physical, textile, and dyeing properties, has practically forced 
itself upon the attention of every branch of textile manufacturing. 
Without doubt the unique dyeing properties of this fiber are fore- 
most in its favor at the present time, for while it offers many other 
and very interesting points for its support, no other fiber can 
even approach it for most white or two-color effects when in com- 
bination with the older and better known fibers. 

At the present time all of the rayons* are in unprecedented de- 
mand, but acetate silk by reason of its dyeing porperties alone, 
holds a certain definite field of usefulness upon which none of 
the older rayons (nitro, viscose and cuprammonium) can even 
encroach. Yet only a few years ago it was these very dyeing 
properties, or rather with the information then available, its lack 
of dyeing properties, that restricted the use of this wonderful new 
fiber. The fact that both the fiber and its dyeing methods, as well 
as most of the dyestuffs themselves, are very new, the two latter 
having been developed especially for this particular fiber, renders 
technical information on these subjects of special interest, espe- 
cially to all textile chemists and dyers, at this time. 

We are all more or less familiar with the older varieties of re- 
generated cellulose rayon which have come into such wide use in 
recent years, their individual and collective properties, methods of 


*The name rayon has been applied as a class designation to the whole 
group of fibers formerly known as artificial silks. However, as pointed 
out by Davies, American Dyestuff Reporter 15, 197 (1926), this does not 
satisfy the technical mind, since the fibers produced by the different 
chemical methods possess different chemical, physical, and dyeing proper- 
ties. It is therefore customary for the technical man to refer to the 
different rayons under the various names which describe the chemical 
processes involved in their manufacture, and he therefore speaks of 
viscose silk, cuprammonium silk, nitro silk, and cellulose acetate silk, ‘acetyl, 
or acetate silk, as we will call it. 


13 


14 ACHKTATE Sia 


dyeing, etc. Acetate silk is an entirely different product in that it 
is a cellulose ester (acetate) and not a regenerated, modified, or 
hydrated form of cellulose, as are the older and better known 
rayons. There is no more relation between the older rayons and 
acetate silk in many of their properties than there is between 
glycerol and olive oil, or alcohol and ethyl acetate. In this instance 
we may compare the older rayons to the gylcerol and the olive oil 
to acetate silk. Cellulose is the basic constituent of all of our 
present rayons, acetate silk included; but in the acetate silk the 
cellulose is combined with acetic acid to form an ester, just as in 
olive oil the glycerol is combined with the fatty acids to give the 
ester which we know as olive oil. With this in mind, we would 
expect quite different properties in the new product, acetate silk, 
and we are certainly not disappointed. No dyer or chemist would 
attempt to successfully substitute glycerol for olive oil, or alcohol 
for ethyl acetate, in very many processes, or vice versa. No more 
can he with uniform success dye acetate silk by the methods 
successfully applied to the older rayons or cotton. 

The original Chardonnet silk was also an ester (cellulose ni- 
trate), and had some properties in common with the acetate silk, 
but as this original Chardonnet silk was very flammable, one of 
the first improvements was a method of rendering it non-flam- 
mable, by denitrating it. This denitration changed it from an 
ester to a hydrated cellulose, which chemically corresponds to the 
present Chardonnet or nitro silk. The fact that acetate silk differs 
so much from the older rayons in constitution and most of its 
properties necessitates a much more detailed discussion of the 
subject of dyeing than would be desirable in the case of a fiber 
more nearly related to a known commercial product, in order to 
give the dyer a full and complete understanding of the subject. 


The Results of Research 
Within the last five years, research upon dyes and dyeing meth- 
ods for acetate silk has possibly developed more new facts and 
theories upon dyes and dyeing, as well as absolutely new classes 
of dyestuffs, than any other research along similar lines since the 
development of the vat dyes. 
Some of these new products are the Ionamines, the “dispersol” 


GENERAL CONSIDERATIONS 15 


and “sulfato” dyes, etc. All of these will be considered later in due 
order. Many of these new dye stuffs have no other use than 
upon acetate silk, but the research, theories, and new products 
are already having an effect upon the dyes for, and the methods of 
application to, the older rayons and natural fibers. 

At the same time, the combined research upon the rayons (col- 
lectively) has enormously increased our knowledge of cellulose 
and related compounds, much to the advantage of the whole textile 
industry, as well as of many others. Sad to relate, the advances 
in the field of our protein fibers, wool and silk, have not kept pace 
with that of cellulose. It is significant to note that most of these 
advances and discoveries have been made in England, where they 
appear to have very well learned the value of research. 


TABLE I 
DoMESTIC RAYON PRODUCTION BY THE PRINCIPAL AMERICAN 
COMPANIES 
Company Production in Pounds 
z First 8 Total 1926 1927 
1925 Mo. 1926 (Estimated) (Estimated) 
MEP HEs VASCOSGICCOnnis Kos os a ee ce 35,000,000 25,000,000 37,000,000 45,000,000 
IDMPOnt Raven COs. cio css ees 6,761,560 6,900,000 11,500,000 15,500,000 
EEAIDIZEPATE SUK CO. sc isa dwiee ee 5,200,000 5,000,000 7,000,000 8,000,000 
Industrial Rayon Corp......... 2,250,000 2,250,000 3,500,000 4,000,000 
American Cellulose &- Chemical 
NY NEE: CEOS ale 4 Sk EE oe 1,500,000 1,500,000 2,500,000 3,500,000 
BSlAmMaseY COLD. ee cas cscs ess sve 675,000 650,000 1,000,000 1,500,000 
PNCINETAT ES SUL CoOnsicis ¢ wccsls srs ss 322,665 250,000 400,000 500,000 
OOUIG GEL ILI Geeet aciatehais.s ois/ened's oie.os 500,000 350,000 500,000 2,500,000 
PC OtALMwt se sles cekia «wie 52,209,225 41,900,000 3,400,000 80,500,000 
Acetate Site 
1924 1925 1926 1927 

ela nese rss chy cite a c.c slivers 08's’ 1,500,000 2,500,000 3,500,000 

STS aot sachs oe ,000b 500,000b 590,000b 


Textile World 68, 1749-50 (1925); 69, 839 (1926); 70, 1996 (1926). 


»As estimated by Textile World; correct figures not available. 


TABLE II 

RAYON PRODUCTION IN POUNDS BY YEARS 
World United States 

ck bs hse secversscs 26,000,000 

OT a 35,000,000 

Ae 40,000,000 
ne Or 50,000,000 9,000,000 
on Es 65,000,000 18,000,000 
vce tbe ke eves 79,738,000 26,000,000 
ee ic uc Gavan ceunee 97,000,000 35,500,000 
A 141,414,000 38,750,000 
or ic o's va o8e ope cs vei 185,000,000 52,200,000 
Lets | 210,000,000 63,400,000 


Textile World, 68, 1749-50 (1925); 70, 1997 (1926). 


16 ACETATE SIG 


TABLE III 
WorRLD RAYON PRODUCTION BY COUNTRIES 
Production 
Country 1922 1923 1924 1925 
United States 23,500,000 35,400,000 39,000,000 52,200,000° 
England 15,340,000 16,500,000 23,947,000 28,000,000 
Germany 12,584,000 13,000,000 23,672,000 27,100,000 
Italy 6,292,000 10,000,000 18,480,000 30,000,000 
France 6,292,000 7,700,000 12,333,200 14,400,000 
Belgium 6,292,000 6,000,000 8,874.800 11,100,000 
Switzerland 1,887,600 3,700,000 4,004,000 5,500,000 
Holland 2,516,800 2,600,000 3,366,000 4,400,000 
Austria 1,573,000 2,640,000 3,500,000 
Poland 943,800 1,540,000 2,200,000 
Czechoslovakia 629,200 1,293,600 2,000,000 
Japan 1,199,000 1,400,000 
Hungary 1,887,600 616,000 700,000 
Spain 184,800 220,000 
Sweden 176,000 176,000 
Russia 88,000 88,000 
Other Countries 2,100,000 
Total 79,738,000 97,000,000 141,414,400 182,984,000 


‘Recent statistics from the U. S. Bureau of Census give 51,800,000 


pounds for 1925. 


Industry Year 


Hosiery 

Knit Goods 
Silk 

Cotton 
Underwear 
Braids 
Upholstery 
Plush 

Wool 
Miscellaneous 


30 


TABLE IV 
THE PERCENTAGE CONSUMPTION OF THE RAYONS BY THE VARIOUS 


TEXTILE INDUSTRIES 


1912 1915 1918 1920 1921 1922) 1923) 1022 


65 40 


| — 
r= bo Go DO dO min 
wn 


23 23 
21 29 
13 12 
10 9 
1 2 
14 10 
2 Z 
3 1 
1 1 
10 11 


24 ae 
26 25 
11 is 
10 11 
+ > 
11 10 
2 2 
i 2 
1 1 
10 7 


23 28 
14 5 
138.5 ety 
15 26 
11 13 
8 A 
2 1 
1 1 
8 6 


CHAPTER II 
THE DEVELOPMENT OF RAYON 


THE credit of first suggesting an artificial silk is usually given 
to Reaumur (1734) but recent! information indicates that this 
rightly belongs to Robert Hooke, author of “Hooke’s Micro- 
graphia” (1665). Undoubtedly Reaumur also suggested artificial 
silk. The following quotations are from page 7 of Hooke’s book. 

“A conjecture, that it may perhaps be possible to spin a kind 
of artificial Silk out of some glutinous substance that may equal- 
ize natural Silk.” 

“A pretty kind of artificial Stuff I have seen, looking almost 
like transparent Parchment, Horn or Ising-glass, and perhaps 
some such thing it may be made of, which being transparent, and 
of a glutinous nature, and easily mollified by keeping in water, 
as I found by trial, had imbib’d, and did remain ting’d with a 
great variety of very vivid colours, and to the naked eye it looked 
very like the substance of Silk. And I have often thought, that 
probably there might be a way found out, to make an artificial 
glutinous composition, much resembling, if not full as good, nay 
better, than that Excrement, or whatever other substance it be 
out of which, the Silk-worm wire-draws his clew. If such a 
composition were found, it were certainly an easie matter to find 
very quick ways of drawing it out into small wires for use. I 
need not mention the use of such an invention, nor the benefit 
that is likely to accrue to the finder, they being sufficiently obvious. 
This hint therefore, may, I hope, give some Ingenious inquisitive 
Person an occasion of making some trials, which if successful, 
I have my aim, and I suppose he will have no occasion to be 
displeased.” 

Schwabe of Manchester experimented on various processes 
for the production of an artificial silk in 1842 but the first patent 
on the subject appears to be that of Audemars of Lausanne, who 
in 1855 attempted to utilize an ether-alcohol solution of nitrocellu- 
lose, prepared by nitrating the bast fibers of the mulberry tree. 


17 


18 ACETATE Silk 


This effort was not successful but in 1882 and 1883, Powell, Wes- 
ton, Swan, Swinburne, and Wyne worked out methods very simi- 
lar to those later adapted by Chardonnet. Chardonnet had his 
first success in 1884 or 1885, but it was not until about 1890 that 
it was really a success, commercially. The British rayon industry 
may be said to date its existance from the work of Cross and 
Bevan on viscose in 1892. 


Cellulose Acetate 


The first reference in the technical literature regarding the 
acetylation of cellulose appears to be that of Schuetzenberger? 
who heated cellulose in a closed tube with acetic anhydride. Wor- 
den,® in an excellent review and discussion of the art of preparing 
cellulose acetate up to 1919, divides the advances in the prepara- 
tion of the ester into three periods: 


1. The academic period, covering from the work of Schutzen- 
berger in 1865 to that of Cross and Bevan in 1894.* 


2. The period 1894 to I9II, important advances indicated by 
the Miles patents.” 


3. The period 1911 to 1919, important advances indicated by 
the Dreyfus patents. 


The early (1st period) methods of preparing cellulose acetate 
are of no particular interest at the present time. They are so ably 
covered by Worden‘ that it is useless to give them in detail here. 

The next important development after Schuetzenberger’s origi- 
nal work appears to be that of Franchimont,® who discovered the 
so-called catalytic action of sulfuric acid or zinc chloride in the 
acetylating reaction. That this discovery marked an important 
step is evident from the fact that even today most of the industrial 
methods of acetylating cellulose utilize sulphuric acid, in one form 
or another, as the catalytic agent. 

The next important development in the field of cellulose acetate 
appears to be the patent of Cross and Bevan*® which marks the 


aBritish Patent No. 9,676. 
"United States Patents No. 838,350, etc. 


THE DEVELOPMENT OF RAYON 19 


beginning of Worden’s second period in the development of the 
acetate. In this patent the industrial value and technical applica- 
tions of cellulose acetate are mentioned for the first time. 

Undoubtedly the most important development during the sec- 
ond period is covered by the patents of G. W. Miles, particularly 
his patents of 1905. Miles’s early patents covered the direct 
acetylation of fibrous cellulose, United States Patent Application 
No. 24,575, dated June 23, 1900, which was allowed December 
18, 1900, abondoned and then included in his application of May 
27, 1901. His United States Patent No. 733,729 (1903) and 
Canadian Patent No. 90,848 (1905), while important, covered 
the production of cellulose acetates soluble only in expensive, toxic 
solvents, such as chloroform and tetrachloroethane. 

His later discovery—covered by United States Patent No. 
838,350 (1906), reissue 12,637 (1907), British Patent No. 19,330 
(1905), French Patent No. 358,079, Belgian Patent No. 187,308 
(1905), Hungarian Patent No. 35,866 (1905), Austrian Patent 
No. 41,461 (1909), Canadian Patent No. 103,045, and German 
Patent No. 252,706—covers a hydrating or hydrolyzing step in the 
preparation of cellulose acetate, wherein the chloroform soluble 
(primary) acetates are converted into acetone soluble (secondary ) 
products. The German Patent covering this process was issued 
only after years of litigation and sale to the Bayer Company, 
who held German Application No. E—20,963, which was added 
to Miles’s Application M-28,289, and covered by the one patent, 
No. 252,706. The value of this process lies in the solubility of 
the hydrolyzed product in comparatively cheap solvents, from 
which it gives filaments and films of good strength and flexibility. 
Many modifications of the original hydrating process have been 
patented, and described in the literature, e.g., British Patent No. 
24,067 (1906); French Patents No. 371,447 (1906), and No. 
428,554 (1910) ; etc.° 

Worden’s third period covers the first Dreyfus patents of July 
5, 1911, British Patents No. 20,975, No. 20,976, and No. 20,977, 
etc. These patents cover the preparation of highly viscous cellu- 


© The products of direct esterification, soluble in chloroform, are designated 
primary acetates, while the hydrolyzed, acetone-soluble products are secon- 
dary acetates. 


20 ACH TASTE \o LIK 


lose acetates and there are certainly a number of them. They 
cover the entire range of cellulose acetate manufacture, including 
the solvents used, etc. The first of these patents points out that 
high viscosity, high tensile strength, and elasticity are comple- 
mentary. The product is soluble in alcohol plus chloroform, or in 
acetone, but insoluble in chloroform alone. 

The original patents upon the manufacture of acetate silk 
appear to be those issued to A. D. Little, W. H. Walker and H. 
S. Mork, the latter now vice-president of the Lustron Company. 
These were United States Patents No. 712,200 of 1902, and No. 
792,149, June 13, 1905, which covered the use of cellulose ace- 
tate prepared according to United States Patents No. 709,922,° etc. 

The scientific, technical, and patent literature from the time 
of Schuetzenberger up to the present, and particularly since 
the world war, is replete with references to research upon cellu- 
lose acetate, acetate silk, dyes for and dyeing methods, and re- 
lated subjects. Worden** covers all of the important develop- 
ments up to 1919, which are entirely too voluminous for the pres- 
ent available space. Since 1919 the bulk of literature upon this 
subject has increased tremendously and can best be reviewed by 
reference to the excellent abstract journals covering the various 
phases of chemical and textile technology. 

Possibly Grandmonyeu was the first to prepare acetate silk in 
1898, but the Lustron Company of Boston appear to have been 
the pioneers in the manufacture of acetate silk on a commercial 
scale, with Bayer and Company of Germany, and possibly the 
Société Chimique des Usines du Rhone of Lyons, France, founders 
of the “Rhodiaseta” Company, closely following. Henckle von 
Donnersmarck Artificial Silk and Acetate Works also appear to 
have investigated the field to some extent and probably manufac- 
tured some acetate silk. Undoubtedly many other firms at various 
times conducted work of a more or less experimental nature upon 
this process. 

Acetate silk was produced in a small way by Dr. Camille and 
Dr. Henri Dreyfus in Basle, Switzerland, in 1910 to 1913. Dur- 
ing the World War these investigators were called to England 


“See page 26. 


THE DEVELOPMENT OF RAYON 21 


to handle the production of cellulose acetate for use in the prepa- 
ration of aeroplane dopes. At the close of the war their attention 
was again given to the production of acetate silk, which resulted 
in the formation of British Celanese, Ltd., and associated com- 
panies® in various countries. Although the plants of this com- 
pany in England had been the world’s largest producers of cellu- 
lose acetate during the war, they did not start the production of 
the present Celanese until about 1918. In the early part of 1921, 
they were producing about 1000 pounds of Celanese daily but 
doubled their capacity during the year. Production has steadily 
increased up to date. 

Celanese was produced in America on a small scale in 1919, 
and large-scale production was started in 1922, with a constant 
increase in capacity. Within the past few years Celanese has 
also been produced in both France and Belgium. One of the most 
recent developments in connection with Celanese appears to be the 
formation of a Canadian Company, the Canadian Celanese, Ltd., 
Dr. Camille Dreyfus, president, to build a $7,200,000 plant at 
Drummondville, Quebec, Canada. 

Acetate silk has been manufactured for some years in France 
by the Société pour la Fabrication de la Soie “Rhodiaseta.” This 
company was founded by the Comptoir des Textiles Artificiels 
and the Société Chimique des Usines du Rhone, the latter company 
having had some previous ten years’ experience in the production 
of high grade, stable, cellulose acetate. While Rhodiaseta yarn 
does not appear to be very well known in America, it enjoys an 
excellent reputation and sale in France and neighboring countries. 
Acetate silk is also manufactured in Switzerland, and several other 
companies are either manufacturing or preparing to manufacture 
acetate silk. 


“The American Cellulose and Chemical Company, Canadian Celanese, 
Ltd., La Celanese Francaise, and others. 


22 ACETATE Silk 


References 


+G. J. Alexander, J. Soc. Chem. Ind. 45, 221 (1926). 

*P. Schuetzenberger, Comp. rend. 61, 485-6 (1865). 

SE. C, Worden, J. Soc. Chem. Ind. 38, 370-4T (1919). 

*E. C. Worden, “Technology of Cellulose Esters”, Vol. VIII, 1916. 
5 A. Franchimont, Comp. rend. 89, 711 (1879) and 92, 1053 (1881). 


CHAPTER IIT 
PREPARATION 


The Acetylation of Cellulose and “Catalysts” Used. “Ripening” 
the Acetate and Its Effect on Solubility. The Manufacture of 
Acetate Silk, Mixed Ester Fibers and Colored Acetate Silk. 


CELLULOSE acetate may be prepared from cellulose in various 
forms, such as cotton or suitably purified wood pulp, acetic an- 
hydride, glacial acetic acid, and a so-called “catalyst’” or condens- 
ing agent, such as sulfuric acid (either alone or in some form of 
combination), phosphoric acid, zinc chloride, anhydrous acetates 
of zinc or manganese, etc. It is understood that in the present 
industrial processes, purified cotton linters or paper pulp is used 
as the basic material and, that sulfuric acid is almost or quite 
universally used as the catalyst. 

From these simple starting materials, by suitable manipulation, 
it is possible to obtain, and is in fact frequently difficult to avoid 
obtaining, a wide variety of resulting products, differing very 
materially in their properties. These variations may start with the 
proportions and nature of the initial ingredients; the temperature 
and duration of acetylation ; the time, temperature, and method of 
“ripening’’, etc., which to a large extent influence the acetate con- 
tent of the resulting product; the method and extent of purifica- 
tion, etc. In the case of acetate silk, this variation may be even 
further complicated by the solvent used in spinning, the methods 
and mechanical apparatus for spinning, the nature of the spinning 
- bath, if one is used, etc. 

That wide differences in the properties of the finished products, 
both as cellulose acetate and acetate silk, do exist is fully recog- 
nized by all those familiar with the industry. An instance of this 
is the differences in our two best known acetate silks, Lustron and 
Celanese. Both of these types have acetylation values higher than 
cellulose diacetate and lower than the triacetate, but Lustron is 
more highly acetylated than Celansee. 

In the manufacture of Lustron,! the cellulose acetate is dis- 


23 


24 ACHAT Aol i sien 


solved in a combination of tetrachlorethane and some cheaper 
solvent, or in chloroform. This solution is forced through the 
spinneret into a hydrocarbon, such as kerosene, in which the sol- 
vent is dissolved and the cellulose triacetate (Lustron) fiber pre- 
cipitated. In the manufacture of Celanese, on the other hand, the 
cellulose acetate is dissolved in acetone or a similar cheap, volatile 
solvent, and the fiber subsequently formed by the evaporation of 
the solvent. Most dyers soon become familiar with the differences 
in the two products, which will be considered more in detail as we 
proceed. 

In order that we may have a better understanding of the whole 
subject as just outlined and its relation to the dyeing and other 
processes on acetate silk, more details regarding the preparation 
of the cellulose acetate may be of interest. 


Acetylation 


Heuser? states that cellulose triacetate is formed according to 
the equation: 
CsH00s5 +3(CHsCO)20 = CgH7O;5(CH3CO)3-+ 83CH3COOH ; 


or, written in another manner: 


CH3C 
H —COCH3 
CH3C 
CH3C 
C,H; 2—OH-+ =—C.H;, 2—O—COCH;3+3CH;COOH 
CH3C 
CH3C 
H —COCH3 
CH3C 
Cellulose Cellulose Triacetate. 


While all readers may not agree as to the exact formula for 
cellulose, the above serves very well to illustrate the principal of 
the reaction. Theoretically, according to this equation, 100 grams 


PREPARATION 25 


of air-dry cellulose, such as cotton containing 5 or 6 per cent of 
water, will require 188 grams of absolute acetic anhydride. How- 
ever, in practice an excess of the anhydride, or 250 to 400 grams, 
per hundred grams of cellulose, are used, according to process. 

From the above equation we see that in the preparation of 
cellulose triacetate, all three of the hydroxy groups are esterified. 
Theoretically, the mono- and di-acetates of cellulose are also pos- 
sible, but it is somewhat doubtful if these are prepared com- 
mercially, except by hydrolysis. Frequently the process which 
should yield these lower acetates by direct acetylation results in a 
mixture of cellulose triacetate and various lower acetates, with 
unacetylated cellulose. Celanese contains only about two acetate 
groups per cellulose molecule and therefore corresponds closely to 
cellulose diacetate; but it is undoubtedly produced by hydrolysis, 
as will be explained under the Miles process and patents. 

Deschiens® divides the processes for manufacturing cellulose 
acetate into two groups: (a) those in which the cellulose acetate 
dissolves; and (b) those in which it does not pass into solution. 
The a processes include those covered by the Miles patents, the 
Usines due Rhone, and most of the Dreyfus patents. Some of 
the Dreyfus patents also cover the b type of process, which does 
not appear to have a very extensive commercial use at this time. 

Cross and Bevan in 1894 received the first patent upon the 
manufacture of cellulose acetate, British Patent No. 9,676. This 
patent claims a compound of cellulose with zinc acetate, which is 
prepared by mixing cellulose hydrate (obtained by various known 
processes, such as precipitating the solution of cellulose in zinc 
chloride, or in cuprammonium solution, or by acting on cellulose 
with sodium hydroxide and carbon disulfide) with zinc acetate. 
The cellulose hydrate from about 100 parts of dry cellulose is 
mixed with 150 parts of crystallized zinc acetate in solution, and 
the mixture is evaporated and dried at 100° C. The second claim 
in this patent is for an acetate of cellulose, prepared by treating 
the zinc acetate cellulose compound in a finely powdered state 
with Ps chloride, the temperature not being allowed to rise 
above 30° C. (86° F.). Two molecules acetyl chloride are used 
for each one a: zinc acetate in the compound. 


26 ACT VAT a bas. 


The product is washed with water and dried. It may be purified 
by treatment with chloroform, which dissolves the cellulose acetate, 
leaving any unacetylated cellulose undissolved. They compared this 
product with cellulose nitrates and state that from its solution in 
chloroform it may be obtained in transparent films or sheets and so 
used as a substitute for collodion, as a special varnish, etc. They 
also mention that it has the property of uniting with oils in suit- 
able solvents of both, and holds the oils in such a way as to give 
films of a much softer texture without any loss of transparency. 
This patent is the first suggestion of a practical use for cellulose 
acetate to appear in the literature. 

United States Patent No. 709,922 (September 30, 1902), 
British Patent No. 20,666 (September 22, 1902), and French 
Patent No. 324,862 (September 30, 1902) to A. D. Little, H. S. 
Mork, and W. H. Walker, have been stated to cover the cellulose 
acetate first used for the production of acetate silk (Lustron) in 
America. These patents specify the treatment of cellulose with 
acetic anhydride in the presence of an aromatic sulfonic acid, with 
or without the addition of a salt of that acid. For example, 100 
parts of cellulose are treated with 350 parts of acetic anhydride, 
5 parts of phenolsulfonic acid, and 5 parts of the sodium salt of 
phenolsulfonic acid. The reaction is effected at about 80° C. 
Naphtholsulfonic acid may also be used. The object of the sodium 
salt is to insure the absence of any free sulfuric acid. 

The foregoing patents possibly exemplify the early types of 
cellulose acetates which, in the form of acetate silk were widely 
described in the literature as almost impossible to dye. These 
products were soluble only in chloroform and other expensive sol- 
vents. The later hydrolyzed products, as first disclosed in German 
Patent No. 252,706 to the Bayer Company and related patents to 
Miles, are soluble in acetone, mixtures of acetone with alcohol, or 
in extreme instances in water alone. No doubt most of the pres- 
ent acetate silks are made from cellulose acetates prepared by the 
hydrolytic process. It would be interesting to compare the dyeing 


* The chloroform soluble, acetone insoluble products of the direct acety- 
lation of cellulose are designated primary acetates, while | the acetone 
soluble product resulting from the hydrolyzing or “ripening” process are 
called secondary acetates. 


PREPARATION a7 


properties of acetate silks prepared by these two different proc- 
esses, with the new special dyes for acetate silk. 


Later Methods 


According to Deschiens® the present processes for the prepar- 
ation of cellulose acetate may be divided into five steps: (1) The 
acetylation of the air-dry cellulose by acetic acid and acetic an- 
hydride in the presence of sulfuric acid (or other chemical com- 
pounds), which acts as a “catalyst.” (2) Hydrolysis, by adding 
water and acetic acid, taking care to avoid precipitation of the 
acetate. (3) Ripening, during which the product is left for a 
period of time, usually for at least 12 hours, at a fixed tempera- 
ture, which varies in different processes and patents. The reaction 
thus continues regularly until the desired stage is reached. The 
duration and temperature of this ripening process have an im- 
portant effect on the solubility and other properties of the result- 
ing product. (4) Precipitation of the acetylated cellulose as a 
white flaky mass by the addition of a large excess of cold water 
containing sufficient alkali carbonate to neutralize the sulfuric acid. 
(5) Washing, centrifuging, and drying at 20 to 30° C. (68 to 86° 
F.) in well-ventilated rooms. 

A very brief consideration of the above steps, even by a lay- 
man, will suffice to show that it is possible to alter the properties 
of the final product without difficulty. In fact, in actual com- 
mercial practice, it has been found extremely difficult to avoid the 
production of variable products, from day to day or even batch 
to batch. The production of an absolutely uniform product at 
all times requires a very close control of all factors and variables, 
which is possible only with the best equipment and skilled atten- 
tion at all times. As in all other rayons, this feature of uniformity 
of product is of the utmost importance and forms the principal 
basis of superiority of different brands over other less uniform 
products. 

According to the Miles patents, as exemplified by German 
Patent No. 252,706, to the Bayer Company, 100 parts of dry, 
scoured cellulose (preferably bleached cotton) is treated at a tem- 
perature below 40° C. (104° F.) with a mixture of 270 to 310 


28 ACETATE SILK 


grams of acetic anhydride, 390 to 410 grams of glacial acetic acid, 
and 3 to 9 cubic centimeters of concentrated sulfuric acid, until the 
cellulose is disintegrated to form a white, nontransparent, pasty 
mass, the temperature being allowed to rise to 50° C. (122° F.). 
As the reaction is exothermic, the temperature is controlled by 
refrigeration. When the temperature begins to fall, the reaction 
vessel is warmed to 50 or 55° C, (122 to 131° F.) and held at this 
temperature for 36 to 40 hours or until the mass becomes more or 
less transparent, less viscous, and the cellulose is apparently in 
solution, forming a heavy, nearly transparent, light brown mass. 
A test portion is removed, precipitated in a large bulk of water, 
washed neutral, and dried, when it should be completely soluble in 
alcohol-free chloroform, but practically insoluble in absolute 
acetone. At this point the acetate is ready for the hydrolyzing or 
hydrating or ripening process. 

A mixture of 60 or 65 cubic centimeters of water and 60 cubic 
centimeters of glacial acetic acid, per 100 grams of original cellu- 
lose, is added slowly to the cellulose acetate solution while stirring 
vigorously to avoid precipitation. This mixture is held at 40 to 
50° C. (104 to 122° F.) for 12 to 16 hours, or until a precipitated, 
washed and dried sample is only plastic in warm chloroform but 
entirely soluble in pure acetone. The entire mass is then precipi- 
tated by pouring it into cold water, washed until neutral, and dried 
at 35 to 40° C. (95 to 104° F.). The yield from 100 grams of 
cellulose is 130 to 145 grams of partially hydrated cellulose acetate. 

The resulting white, fibrous mass of secondary cellulose acetate 
is soluble in formic or acetic acids with some difficulty; readily 
soluble in tetrachlorethane, acetone, chloroform containing alcohol ; 
less soluble in ethyl acetate, nitrobenzene and pyridine. It is in- 
soluble in water, ethyl or amyl alcohol, amyl acetate, carbon tetra- 
chloride, benzine, benzene, toluene or xylene. It is plastic in hot 
chloroform ; soluble in hot 70 per cent aqueous ethyl alcohol from 
which it gelatinizes on cooling; plastic in glycerol at 125° C.; and 
soluble in a mixture of hot ethyl alcohol and benzene from which it 
is precipitated on cooling. 

As an example of the early Dreyfus patents and methods, French 
Patent No. 478,023 (1914) to H. Dreyfus serves very well. A 


PREPARATION 29 


hundred kilograms of cellulose (cotton or paper) containing 3 to 
6 per cent of moisture are stirred into an acetylating bath at 0° C. 
(32° F.) containing a mixture of 300 to 400 kilograms of glacial 
acetic acid, 250 kilograms of acetic anhydride, and 10 to 15 kilo- 
grams of sulfuric acid. The temperature soon rises to 5 to 15° C. 
(41 to 59° F.) and later falls to 5 or 10° C. (41 to 50° F.). The 
cooling is then discontinued, and the temperature allowed to rise 
as high as 15 or 20° C. (59 to 68° F.). Cooling is again started 
and the product stirred until the temperature falls. The mixture 
is allowed to stand until all fibers disappear, and water is added to 
promote hydrolysis, as in the Miles process. With proper tem- 
perature control, this process is stated to yield a product of high 
viscosity, insoluble in chloroform but soluble in acetone, etc. 

According to British Patent No. 139,232 (1918) to J. O. Zdano- 
wich, a good grade of cellulose acetate suitable for the manufac- 
ture of acetate silk may be prepared by treating 150 grams of puri- 
fied cellulose with a mixture of 500 cubic centimeters of glacial 
acetic acid and 420 cubic centimeters of acetic anhydride. While 
agitating, chlorine gas is passed into the mixture at 70 to 80° C. 
(158 to 176° F.). After two or three hours, 2 grams of sulfuric 
acid are added and stirring continued until a clear solution is 
obtained. 

British Patent No. 258,020, June 17, 1925, to H. J. Mallabar 
states that cellulose acetate which is soluble in acetone, free from 
sulfuric acid residues, and does not char when heated, may be 
prepared by acetylating cellulose in the absence of sulfuric acid, but 
after a pretreatment with a mixture of acetic and sulfuric acids, 
the sulfuric acid being subsequently neutralized before the acety- 
lation proper is effected. Zinc chloride is used as a catalyst during 
the acetylation. For example, 100 parts of cellulose are treated 
for 24 hours with a cold mixture of 400 parts of acetic acid and 
2 to 5 parts of sulfuric acid, and then 200 parts of acetic acid, 
containing sufficient sodium acetate to convert the sulfuric acid 
into sodium sulfate, 15 to 25 parts of zinc chloride, and 250 to 
400 parts of acetic anhydride are added, and the mixture is main- 
tained at 30 to 40° C. until acetylation is complete. The resulting 
cellulose acetate may be precipitated directly from the product 


30 ACETATE Sige 


and afterwards converted into an acetone soluble form by dissolv- 
ing it in acetic acid, and maintaining the solution at 100° C. 

Ost* states that some primary acetates show a partial but fugi- 
tive solubility in acetone; and while their films from chloroform 
are good, those from acetone are poor and can only be partially 
redissolved in acetone. On the other hand the acetone films from 
the secondary products are good, and complete solubility in acetone 
is a permanent characteristic. He also states that a “pure cellulose 
triacetate” may be obtained by treating 100 parts of cellulose, puri- 
fied by treatment with dilute caustic soda and containing 5 to 6 
per cent of moisture, with 400 to 500 parts of acetic anhydride, 
400 to 500 parts of glacial acetic acid and 50 to 100 parts of fused 
zinc chloride. After about three weeks’ time at 20° C. (68° F.), 
the triacetate is obtained, containing 62.5 per cent of acetic acid. 
At 10 or 12° C. (50 or 54° F.), several months’ treatment are re- 
quired to complete the reaction. Higher temperatures (60 to 70° 
C.) shorten the period of esterification but cause considerable 
breaking down of the cellulose molecule, and the resulting product 
is of little value. The triacetate formed at 20° C. (above) dis- 
solves in pure chloroform but is more soluble in the presence of 
some alcohol, in which case viscous solutions may be obtained. As 
a primary acetate it is not soluble in acetone. 

Barnett’ prepared cellulose acetate from filter paper by pouring 
200 grams of glacial acetic acid, containing just sufficient chlorine 
to color it, on 50 grams of the paper. After standing for some 
time, 250 grams of acetic anhydride were added, and a few bubbles 
of sulfur dioxide passed through the mixture. The temperature 
at once increased, and when maintained at 65° C. (149° F.) by 
cooling, a clear solution of cellulose diacetate (?) was obtained in 
about an hour. This product was soluble in chloroform, acetone, 
pyridine, aniline, hot nitrobenzene; and slightly soluble in a mix- 
ture of benzene and alcohol. 

In another experiment, 5 grams of filter paper was immersed in 
20 cubic centimeters of glacial acetic acid and 20 cubic centimeters 
of acetic anhydride containing 0.32 gram of chlorine added. Then 
® cubic centimeters of acetic anhydride containing 0.26 gram of 
sulfur dioxide were further.added, whereby the mixture rapidly 


PREPARATION 31 


_gelatinised and solution was complete within 5 minutes. White 
flakes of cellulose triacetate were separated from the product.* 


It is understood that at the present time, cellulose acetate is pre- 


| pared” on a commercial scale in the Rhone district of France by 


treating the cellulose in large mixers with the acetic and sulfuric 


/ acids and 20 or 25 per cent of the acetic anhydride in small quan- 
_ tities at a time and then adding the balance of the acetic anhydride 
necessary to complete the reaction. The cellulose is quickly acted 
| upon, soon losing its structure and dissolving to a clear solution. 
| This chloroform soluble product is “ripened” by the action of water 
_and heat until the desired properties are obtained, when the solu- 
tion is further diluted with water to precipitate the cellulose ace- 
tate. On an average with various processes, 100 parts of cotton, 


350 parts of glacial acetic acid, and 400 parts of acetic anhydride 


_ yield 150 parts of primary cellulose acetate. A large part of the 
acids are recovered from the process. 


When cotton is immersed in a mixture of 50 parts of acetic 


_ anhydride, 50 parts of glacial acetic acid and 4 to 6 parts of sul- 


furic acid at 30 to 40° C. (86 to 104° F.), it rapidly dissolves to 


form 


(CgH;O) 4SOs(CoH302) 10 


Thus, as in the nitration of cellulose, the acetylation is incomplete 


in the presence of sulfuric acid. The acetic acid content in this case, 
if cleavage of the molecule is avoided, is only 59 to 61 per cent and 


- sulfoacetate is formed simultaneously, the quantity depending upon 


the amount of sulfuric acid used as catalyst. Pure, high mole- 


cular acetates, free from sulfoacetates, cannot be prepared with 


sulfuric acid as catalyst. At a temperature of 10 to 15° C. (50 
to 59° F.), two to four days acetylation in the presence of 5 or 
10 per cent of sulfuric acid gives the best result. Prolonged 


acetylation at low temperatures appears to increase the amount 
of combined acetic acid in the product, with a consequent de- 
crease in the amount of combined sulfuric acid. With increasing 


time and temperature, the sulfuric acid causes a greater acetoly- 


*Also see U. S. Patent No. 1,600,159, September 14, 1926, to Zdanowich. 


’Probably by a process similar to British Patent No. 237,567, July 28, 
1924, to the Société Chimique des Usines du Rhone. 


32 ACETATE Site 


tic decomposition of the cellulose molecule. When only 1 or 2 
per cent of acid is used the acetylation is complete in a few hours 
at 35 to 40° C. (95 to 104° F.) 

When used as catalyst, acids combined with weak bases are far 
more moderate in their action on the product than sulfuric acid. 
For instance, when methylamine sulfate is used as catalyst, tem- 
peratures may be increased to 35 or even 50° C. With 5 to 10 
per cent of methylamine sulfate at 35° C., several days are neces- 
sary for the complete acetylation; but the molecular cleavage is 
slight even in ten days. At 65 to 70° C. the danger is increased 
considerably, but the acetylation is complete in two hours. The 
composition of this methylamine sulfate cellulose acetate is similar 
to that obtained with sulfuric acid but it contains less sulfoacetate. 
According to Ost,* pure acetates of low acetic content are difh- 
cult to obtain as primary acetates. If insufficient acetic anhydride 
is present to form the triacetate, a portion of the cellulose remains 
unaltered while the composition of the acetate formed approaches 
that of the triacetate. Insufficient time or catalyst. (zinc chloride) 
affects the final product in the same manner. 

Unsaturated esters are readily obtained with either an excess or 
a deficiency of acetic anhydride, if a large proportion of sulfuric 
acid or methylamine sulfate is used. The acetic acid content of 
the final cellulose acetate may fall to 48.5 per cent (diacetate), 
and even below 40 per cent, but with a simultaneous rise of com- 
bined sulfuric acid of from 2.3 to 7 per cent. These mixed esters 
are partially hydrolyzed on precipitation with water; are in- 
creasingly insoluble in chloroform, in which they swell; but dis- 
solve with increasing sulfuric acid content in alcohol and finally 
in water. While pure cellulose triacetate may be preserved for 
years and is not affected by boiling water, products containing 
sulfoacetates split off sulfuric acid on boiling in water.° 

It is interesting to note here that Caille® found that acetate silk 
which contains combined sulfuric acid resists hydrolysis even on 
heating with water at 120° C. (248° F.), if the sulfuric acid 
groups have been neutralized by washing with calcerous water. 
_ Any unneutralized portion of such groups readily split off on 
heating the acetate silk with water. 


© See page 36. 


PREPARATION 33 


__ According to Ost,* only a portion of any primary cellulose ace- 
| tate is extracted by pure acetone, this extraction being least in the 
| case of a zinc chloride triacetate and most in the case of a methyl- 
| amine sulfate product, often amounting to from 50 to 80 per cent 
of its weight. While the chloroform solubility.is constant, the 
acetone solubility is not. An acetone film from a primary acetate 
_made by the solution method is only partly soluble in acetone a 
second or third time. None of the true primary triacetate is 
' soluble in acetone; but only secondary acetates which result from 
_ partial hydrolysis. Ten per cent of aqueous mineral acid at 20° 
C. or 1 per cent at 100° C. (212° F.) produces hydrolysis of the 
| triacetate and may not give an acetone soluble product. Real and 
permanent acetone solubility is produced by partial hydrolysis of 
primary acetates of low acetic acid content and high sulfuric acid 
_ content, by stirring a little acid water into the finished acetylated 
syrup.* 

Exceptional acetone solubility results upon heating a primary 
| cellulose acetate or the primary syrup, after neutralization of the 
sulfuric acid, with ninety-five per cent acetic acid for sometime. 
Hydrolysis takes place in from twenty-four to ninety-six hours to 
a combined acetic acid content of from 56.2 to 50.8 per cent. 
Heating in the presence of small quantities of catalysts, such as 
sodium bisulfate, gives similar results. Heating with aniline or 
phenol, in the presence of a little water, also hydrolyzes it to the 
acetone-soluble form. Solubility in acetone is not connected with 
any definite degree of hydrolysis, the limits of the combined acetic 
acid varying between 57.6 and 50.9 per cent or even more widely. 

Primary acetates prepared from previously hydrolyzed cellulose 
are very similar to those prepared from ordinay cellulose. The 
resulting films appear to be just as good, but generally the solu- 
tions are of lower viscosity and the precipitated products are more 
pulverulent. Hydrocellulose is more readily acetylated than or- 
dinary cellulose, the reaction proceeding more rapidly with a 
smaller quantity of catalyst and at a lower temperature. Secondary 
acetates are produced from these products in the same manner as 
from those prepared from normal cellulose. 


4See German Patent No. 252,706. 


34 ACETATE Sik 


“Catalysts” 


While the sulfuric acid used in acetylating cellulose is usually ~ 
spoken of as a catalyst or as a condensing agent, its function ap- — 
pears to be almost entirely due to its degradating action upon the 
cellulose, with the consequent formation of hydrocellulose. Various 
workers have shown that the acetylation of hydrocellulose is much 
more rapid than that of cellulose. It is therefore possible that, as 
the mineral acid acts upon the cellulose to form hydrocellulose, 
this product is immediately broken down to form the cellulose 
acetate. 

Heuser? in discussing the role of catalysts in the acetylation 
process, divides the action of sulfuric acid, either free or combined, 
into four stages: 


1. Hydrolysis of the cellulose to cellulose dextrin. 


2. Esterification of the cellulose dextrin with sulfuric acid to 
sulfuric acid esters of cellulose dextrin. 


3. Esterification of the sulfuric acid esters by means of acetic 
anhydride, forming sulfoacetates. 


4, Splitting off of the sulfate residues ; that is, the establishment 
of a definite ratio between sulfate and acetate residues, de- 
pendent upon the conditions of the experiment. 


He also points out the hydrolysis of zinc chloride in solution, 
and says that it is very evident from the quantity of these materials — 
required in the acetylation process that their role is not strictly 
that of a catalyst. While they do start and accelerate the reaction, 
their part is, possibly, principally that of a peptizing agent, rather 
than that of a catalyst. These catalysts no doubt act on the 
cellulose in such a manner as to render it more reactive with the 
acetic anhydride; and while in most instances their action on the 
cellulose is not great, the resulting acetate is not a pure cellulose — 
acetate, when they are used. Acetic acid acts as a solvent for the 
reaction as well as the acetate formed; but alone, it has very little | 
esterifying action on cellulose even at high temperatures. 

Barnett,® in discussing the catalysts, says that most of them are — 
strong dehydrating agents and as examples mentions sulfuric acid, 


PREPARATION 35 


pltosphoric acid, zinc chloride, chlorides and oxychlorides of sulfur 
and phosphorous, dimethylsulfate, chloroacetic acid, etc. Chlorine 
does not react readily except under special conditions and then 
only slowly. Sulfuric acid tends to give dark colored solutions 
and to hydrolize the product. It may also cause brittleness in the 
resulting film, due to its incomplete removal. Sulfuryl chloride® 
is claimed to give a superior product. Either chlorine or sulfur 
dioxide alone give poor results as catalysts; but when traces of 
both are introduced either separately or together, the acetylation 
proceeds to a remarkable extent, giving a prefectly clear solution 
or jelly. This catalyst is also useful in the preparation of other 
cellulose esters, such as the butyrate, benzoate (using benzoyl 
chloride in acetic acid), etc. He attributes the great reactivity of 
this mixed catalyst to a possible condensation of the chlorine and 
sulfur dioxide upon the cellulose itself, which produces a small 
amount of sulfuryl chloride im statu nascendi in intimate contact 
with the cellulose. The reaction proceeds best when the amounts 
of chlorine and sulfur dioxide are approximately in the ratio of 
their molecular weights. 

_Levy in a recent patent* proposes the use of some new catalytic 
agents in connection with the preparation of cellulose acetate. He 
states that acetone soluble cellulose acetate may be rapidly prepared 
by treating air-dry cellulose, which contains 6 to 7 per cent of 
moisture, with a mixture containing acetic acid, acetic anhydride, 
a condensing agent such as sulfuric acid, and a catalyst such as 
the acetate or sulfate of vanadium, nickel, cobalt, or chromium. The 
metallic salt apparently has the function of a true catalyst, the 
metal being the active element, and therefore it may be introduced 
in the metallic form, passing gradually into solution as the reaction 
proceeds. 

For example: 25 pounds of cellulose are kneaded at a tempera- 
ture not exceeding 15° C. in a mixture containing 5 pounds of 
acetic acid, 5 pounds of acetic anhydride, 0.2 pound of sulfuric 
acid and 2.5 grams of chromium acetate, until a transparent, vis- 
cous liquid, free from fibers is obtained. This mixture is then 

* See British Patent No. 24,382 of 1910. 


* Also see British Patent No. 139,232. 
£L. A. Levy, British Patent No. 240,624, April 9, 1924. 


36 ACETATE Signe 


held at 30° C. until the resulting cellulose acetate is freely soluble 
in acetone. The preparation is complete in 18 hours or less. 
Salts of magnesium, aluminum, sodium, antimony, uranium, man- 
ganese, cerium, tin, niobium and thorium are not suitable catalysts. 


Stability 


Caille® has shown that the stability of cellulose acetate in the 
presence of hot water is very considerably increased by the pres- 
ence of sulfuric acid groups which have been neutralized by 
means of calcerous water (lime). If these sulfuric acid groups 
are not neutralized in this manner, but remain combined with the 
cellulose ester or free, the resulting technical cellulose acetate is 
more or less unstable and subject to decomposition, the extent 
depending upon the amount of mineral acid present in the product. 
It has recently been shown that the sulfuric acid groups present 
in cellulose ester silk (acetate or nitro) greatly influence its dyeing 
properties. Entat and Vulquin™ state that the amount of sulfuric 
acid present as sulfoacetic acid in technical cellulose acetates of 
good grade does not exceed 0.03 per cent, but that in every case 
where sulfuric acid or its derivatives are used as catalysts, the 
resulting product contains some mineral acid combined as a sulfo- 
acetic acid ester of cellulose. 

They state that the free sulfuric acid may be estimated by digest- 
ing a 10 gram sample with 200 cubic centimeters of water at 15° C. 
for 30 minutes, filtering and titrating the filtrate electrometrically 
with standardized barium hydroxide solution. The electrometric 
titration curve shows a sharp break when the free sulfuric acid is 
neutralized. They determine the sulfoacetates present by heating 
a 5 gram sample with 50 cubic centimeters of water for 5 hours 
at 125° C. in an autoclave. The sulfuric acid resulting from the 
hydrolysis of the sulfoacetate is then titrated as above. 


Solubility of Cellulose Acetate and Acetate Silk 


A. Eichengruen has pointed out that a whole series of cellulose 
acetates, many of them more or less indistinguishable from each 
other analytically, are possible and exist in some cases. There are 


PREPARATION 37 


many reasons for this variation in composition, as we have seen in 
the discussion of their manufacture, etc. Probably the greatest 
analytical differences are apparent in the mono-, di-, and tri- 
acetates, yet many others are possible. Our two best known 
acetate silks, Celanese and Lustron, differ considerably in their 
acetate content, the Lustron containing a considerably larger pro- 
portion of acetate groups than Celanese. In the case of cellulose 
nitrate, it has long been known that its alcohol-ether solubility is 
not a function of the nitrogen content alone. In the case of the 
cellulose acetates, probably even a wider discrepancy exists be- 
tween the total acetate content and the solubility in any one sol- 
vent or solvent mixture. For this reason it is rather difficult to 
specify the solubility of cellulose acetate in any solvent or mix- 
ture of solvents with diluents or other compounds. 

One of the factors, which complicates this matter, is that of 
hydrolysis after the acetylation. The primary cellulose triacetate is 
soluble in chloroform, while the partially hydrolyzed secondary 
product is less soluble in chloroform but more soluble in acetone, 
depending upon the extent of the hydrolysis. The constitution of 
these partially hydrated or hydrolyzed cellulose acetates varies 
gradually from complete solubility in chloroform to incipient plas- 
ticity in cold or warm chloroform, with a parallel increasing solu- 
bility in anhydrous acetone. 

Carried beyond this point, the hydrolysis results in products of 
less value, but greater solubility in mixtures of acetone and water, 
until eventually products soluble in benzene, benzine, and finally 
in water alone, result. Worden® states that coincident with 
hydration is the loss of acetic acid, but the stages are indistinguish- 
able, and the solubility results are not always dependent upon the 
acetic acid content. Hydrolysis of the cellulose aggregate in the 
ester appears to take place coincident with elimination of acetic 
acid, so that two variables are simultaneously introduced. For 
this reason the majority of the solubility determinations found in 
the technical literature are practically worthless for systematic 
generalizations, because the nature of the normal (primary) or 
hydrated (secondary) cellulose acetate used in the experiments 


38 ACET ALE SIG 


is not stated, or the conditions under which the determinations 
were made are not recorded. 

Hess? attributes the variable solubilities of cellulose triacetate in 
its different forms as due to the influence of small quantities of 
impurities. The triacetates which are soluble in chloroform or 
tetrachlorethane show a specific rotation with sodium light of 
approximately —20° in these solvents and —50° in pyridine. 
They can be produced in the form of large crystals from solutions 
in tetrachlorethane or in ethylene-tetrachloride. Presumably these 
acetates form molecular combinations with the solvents. The lower 
acetates, soluble in acetone, show a specific rotation, with the 
same light, of only about —21° in pyridine. He also states that 
the ideas of polymerisation and depolymerisation of the cellulose 
molecule are untenable, and that it reacts as a chemical unit 
CegH 00s, rather than as CygHooO1o. Herzog and Kruger! report 
that their experiments indicate that cellulose acetate disperses in - 
acetone when the diameter of the particles is less than 20 ww, in 
ethyl acetate when less than 5 ##, and in epichlorohydrin when less 
than 35 ue, 

The following is a list of some of the most common chemicals 
which have considerable solvent power for some or all of the 
cellulose acetates. No attempt will be made to enumerate the non- 
solvents, for in many cases, in the presence of other compounds, 
usually cellulose acetate solvents, some of the so-called non- 
solvents aid materially in the solution of the acetate. The com- 
pounds enumerated below should never be present in scouring 
baths or dry-cleaning solvents for use upon materials containing 
acetate silk. 

Chloroform, acetone, tetrachlorethane, alcohol of various 
strengths, phenol, cresols, light acetone oil, acetic acid, nitro- 
benzene, pyridine, aniline, triacetin, toluidine, xylidine, mono-, di-, 
and epi-chlorhydrin, acetylene tetrachlorde and ethyl acetate, 
benzyl alcohol, diacetone alcohol, cyclohexanone and other cyclic 
ketones of the same series, etc.” 


" Also see Chapter V on Identification of Rayons, and Worden, “Tech- 
nology of Cellulose Esters.” Vol. VIII. 


PREPARATION 39 


Manufacture of Acetate Silk 


As to the actual conversion of the cellulose acetate into acetate 
silk, very little outside of the patent literature has been published. 
Without doubt the cellulose acetate is thoroughly washed until 
free of acid, the sulfuric acid neutralized, and the ester dissolved 
in a suitable solvent, for spinning. Very possibly, in the case of 
Lustron,* this solvent solution contains tetrachlorethane. In the 
manufacture of Celanese, probably a more volatile solvent is used, 
such as acetone, perhaps in combination with other solvents or 
diluents. 

The formation of the acetate silk fiber from these solvent solu- 
tions differs very considerably in that with Lustron, and prob- 
ably some other products, the fiber is formed by spinning the solu- 
tion into a suitable precipitating bath; while in the case of Celan- 
ese, and possibly in that of all related companies, the “dry spin- 
ning”’ process is used, wherein the fiber is formed not by precipita- 
tion, but by the evaporation of the solvent in a current of warm 
air. From the information available and patents' which have been 
granted to the manufacturers, it would appear that Rhodiaseta 
is manufactured by the dry spinning process, probably in a man- 
ner more closely resembling the Celanese process than that of 
Lustron. 

United States Patent No. 1,551,112, August 22, 1923, to H. S. 
Mork and C. F. Coffin, Jr., assignors to the Lustron Company, 
covers the use of a solvent solution containing tetrachlorethane 
and an aliphatic hydrocarbon for the cellulose acetate, and this is 
spun into a coagulating bath containing an aliphatic hydrocarbon. 

British Patent No. 165,519, March 26, 1920, to the British 
Cellulose and Chemical Manufacturing (Parent) Company and 
H. B. Roy, covers the production of artificial threads and filaments 
by spinning solutions of cellulose acetate, or other cellulose deriva- 
tives in volatile solvents, downwards through a hollow casing in 
a current of warm air, to remove the solvent. The finished thread 
is passed through a small hole in the side of the casing and wound 
by suitable apparatus. A travel of 2 or 3 seconds in a current 


See United States Patent No. 1,583,475. 


40 ACE TATE Sil 


of air at 30 to 50° C. (86 to 122° F.) removes the solvent effi- 
ciently. 

British Patent No. 248,696, May 27, 1925, to G. B. Ellis, from 
the Soc. Fabr. de la Soie ‘““Rhodiaseta,” states that in dry spinning 
solutions of cellulose derivatives in volatile solvents, the cross- 
section of the filaments may be controlled, so as to avoid flat scin- 
tillating effects and obtain the rounder or star-shaped type, by 
ensuring at the spinning apertures an imput of heat, maintaining at 
the spinning dies and in the immediate neighborhood a tempera- 
ture regulated and varied according to the demand of the other 
spinning conditions, independently of the temperature of the cell. 

United States Patent No. 1,583,475, May 4, 1926, to J. E. G. 
Lahousse, assignor to the Soc. Fabr. de la Soie ‘““Rhodiaseta,” and 
British Patent No. 238,842, cover the preparation of acetate silk 
fibers from a solution of cellulose acetate in a volatile solvent by 
the dry spinning process. The evaporating medium, previously 
richly laden with a definite proportion of the vapors of the solvent 
but not saturated at the temperature of the cell, is introduced into 
the closed cell so as to control the speed of drying of the fiber. In 
this way they claim to be able to control the cross-section of the 
filaments. 


Fibers of Mixed Cellulose Esters 


From time to time numerous patents have been granted for 
rayon fibers consisting of more than one variety of cellulose ester, 
or other mixture of cellulose compounds. While these patents 
represent an interesting possibility, if these fibers are now prepared 
on a commercial scale, they have not as yet found any consider- 
able use in America. However, they may eventually appear upon 
the market. The following patents serve as examples of the pro- 
posed fibers: 

British Patent No. 11,625, May 17, 1909; French Patent No. 
402,072, April 15, 1909; German Patent No. 240,751, July 4, 
1908, and No. 248,559 (1909) to L. Lederer cover the produc- 
tion of fibers of a mixed constitution containing cellulose acetate. 
For instance, a spinning solution containing 5 or 6 parts of cellu- 
lose trinitrate, to 2 parts of triacetate, in 27% parts of acetone 


PREPARATION 41 


and 16 parts of acetylene tetrachloride is suggested. Precipitation 
is effected by alcohol. The resulting fiber may be denitrated, and 
it is claimed that the resulting thread has a good strength even in 
the moist condition and may easily be dyed. 

British Patent No. 211,889, February 23, 1924, to W. J. Mel- 
lersh-Jackson, for the Tubize Artificial Silk Company of America, 
covers the production of clear lustrous rayon threads or like prod- 
ucts by spinning solutions of cellulose nitrate in admixture with 
organic acid esters of cellulose; for instance, cellulose acetate, in 
acetone or its homologues, or mixtures thereof, with other solvents 
such as ethyl alcohol. The solvent is extracted from the filament 
by the action of a concentrated aqueous solution of calcium chlo- 
ride, which has no effect on the cellulose esters and is miscible with 
acetone. The solvent is of course recovered from the calcium 
chloride solution. The threads produced by this process are de- 
nitrated in the usual manner. 


Manufacture of Colored Acetate Silk 


As a result of the early difficulties in dyeing acetate silk, not all 
the research was directed towards the production of new and 
special methods of dyeing, and dyes for, this new fiber. Another 
phase of this research led to certain processes and patents for the 
manufacture of a colored artificial silk. 

One of the first processes along this line was British Patent 
No. 1556 of 1911, to F. Bayer and Company, also covered by 
French Patent No. 427,445, March 16, 1911; German Patent No. 
237,210 of 1910; Austrian application A2376-11, March 16, 1911; 
Belgium Patent No. 233,786 of 1911; and United States Patent 
No. 994,738, June 13, 1911, to E. Friedman. According to this 
process, the cellulose is dyed before acetylation with dyestuffs 
capable of withstanding acid treatment and then acetylated in the 
usual manner. Suitable dyes mentioned are Algol Red, Helindone 
Scarlet, Rosanthrene, Diazo Brilliant, Scarlet, Algol Blue, Indan- 
threne Blue, Katigen Brilliant Green, Katigen Violet, Diazo Indigo 
Blue, Katigen Black or Immedial Black. In the case of, Katigen 
Brilliant Green G, a sulfur dyestuff, 10 per cent on the weight of 


42 ACH TAT Re a lisk 


the goods is suggested, and it is claimed that in most instances 
the color is even purer in the acetate silk than on cotton. 

W. G. Lindsey, assignor to the Celluloid Company, in United 
States Patents No. 1,041,115-6-7 and 8, October 15, 1912, men- 
tions that acetyl-cellulose, soluble in acetone, may be mixed with 
camphor, triphenyl or tricresyl phosphate, methyl or ethyl alcohol, 
etc., and coloring matters or other inert substances. 

According to United States Patent No. 1,041,587 (October 15), 
British Patent No. 12,995 (June 3, 1912), Belgium Patent No. 
246,562 (1912), D. R. Anm. B-63, 482 (1911), and French 
Patent No. 444,588, to B. Borzykowski, a colored acetate silk may 
be manufactured by dissolving the dyestuff, such as Bismark 
Brown, Chrysophenine G, Fast Scarlets, substantive blacks, etc., 
directly in the acetylating bath, before the introduction of the 
cellulose. When the cellulose acetate is precipitated for purifica- 
tion the dyestuff remains in the acetate, giving a bright and clearly 
dyed product. Resolution of the cellulose acetate in cholorform, 
acetone, or dichlorethylene gives a clear solution without alteration 
in shade. 

British Patents No. 226,309, October 10, and No. 227,146, 
October 19, 1923, to L. A. Levy, propose to color the acetate silk 
by adding suitable dyes to the acetone solution of the cellulose 
acetate, before dry spinning (Celanese process). 


References 


*G. J. Esselen, Jr., American Dyestuff Reporter 15, 166-8 (1926). 

* E. Heuser, “Textbook of Cellulose Chemistry,’ Translation by West and 
Esselen, Ist Edition 1924, pg. 45. 

*'M. Deschiens, Chemistry and Industry 44, 902-7 (1925). 

*H. Ost, Z. angew. Chem. 32, 66-70, 76-9, 82-9 (1919). 

°W. L. Barnett, J. Soc. Chem. Ind. 40, 8 (1921). 

°A. Caille, Chim. et Ind. 13, 11-13 (1925). 

“E. Heuser, loc. cit., pg. 50. 
ae i C. Worden, “Technology of Cellulose Esters,’ Vol. VIII, 1916, pg. 

°K. Hess, Z. angew. Chem. 37, 993-1003 (1924). 

** Herzog and Kruger, Naturwissenschaften 13, 1040-2 (1925). 

*Entat and Vulquin, Ann. Chim. Analyt. 4, 131-5 (1922). 

“F. Sproxton, “Cellulose Ester Varnishes,” 1925. 

*%J. Foltzer, “Artificial Silk and Its Manufacture,” Transalation by 
Woodhouse, 3rd Edition, 1926. 

* Anon, Silk J. 2, No. 22, 48 (1926). 


Srv LE RVLV 


Piet eRAI, PROPERTIES OF ACETATE SILK 
feel) DYEING PROPERTIES) 


Its Resistance to Water, Acids, Alkalies, and Micro-Organisms. 

The Relation of Regain to Strength and Elasticity. Electrical 

Properties, Flammability, Luster, Specific Gravity, Refractive 
Index, and Structure. 


FRoM our present knowledge of the constitution of acetate silk, 
we would expect it to have somewhat different properties from 
those of the older rayons, none of which approach it in chemical 
composition; and many of these properties of acetate silk are 
highly desirable in a textile fiber. In fact in some respects this 
product more closely resembles true silk than any other known 
fiber. It has a high luster; good tensile strength which it retains 
to a greater extent than the other rayons when wet; a high elas- 
ticity, especially in the case of Celanese; a soft, full, silky feel in 
the fabric; an extremely high resistance to micro-biological injury 
such as mildew, mold, and bacteria; a high thermal and electrical 
insulating value; a low flammability ; low specific gravity; etc. Its 
dyeing properties are also especially interesting, but we will not 
attempt to discuss them in the present chapter. 


Water Resistance and Wetting-Out 


Acetate silk does not swell appreciably in either hot or cold 
pure water nor in absolute alcohol, but swells in mixtures of water 
with alcohol or many other organic solvents. It has a high resis- 
tance to wetting-out with pure water, and its strength when wet is 
proportionately greater than that of the other rayons, as shown in 
the various tables which follow. Cold water alone has little detri- 
mental action on the fiber even when in contact for long periods of 
time. The resistance to hot water varies with the product. In 
the case of Celanese and Rhodiaseta, boiling water destroys the 
luster, therefore it should not be wet-processed (scoured or dyed) 


43 


d4 ACETPATIA Asia 


at over 82° C. (180° F.). On the other hand, Lustron will with- 
stand boiling water for sometime without ill effects. 

In fact, the older or original acetate silks (primary cellulose 
triacetates ) were so hard to wet-out with aqueous solutions that it 


| 
| 


a b c d @ r2 
FIGURE I 
Showing Viscose (a), Du Pont (b), Industrial Fiber (c), Lustron (d), 


Celanese (e), and Cuprammonium (f) Silks 
Courtesy Associated Knit Underwear Manufacturers of America 
was almost impossible to wet them out completely and evenly in a 
practical way with aqueous solutions of the ordinary dyeing mate- 
rials. Apparently, as might be expected, the present-day hydrolyzed 
or secondary cellulose acetate silks are much easier to wet-out than 


GENERAL PROPERTIES 45 


the older products. Of our present acetate silks, Lustron which 
approaches a triacetate in composition, is no more difficult to 
wet-out than Celanese, which more nearly corresponds to a cellu- 
lose diacetate. This may be due to some special treatment during 
its manufacture, or to some finishing process. Again it is possible 
that in the case of Lustron, the addition of suitable compounds to 
the spinning or precipitating solutions may aid in wetting-out the 
finished product. 

For instance, United States Patents No. 712,200 (1902), and 
INO 192,149, June 13, 1905, to A. D. Little, H. S. Mork, and 
W. H. Walker, cover the addition of compounds such as oleic 
acid, phenol, cresols, etc., to the cellulose acetate in order to render 
the acetate silk more pliable. It is well known that the three com- 
pounds mentioned above considerably lower the surface tension 
of aqueous soap solutions, and it is very possible that they play 
an important part in wetting-out Lustron. 


Regain 

Acetate silk normally has the lowest regain of any commercial 
textile fiber and does not take up the moisture or water to the 
same extent as the other textile fibers, including the older rayons. 
The low permeability of acetate silk to water and aqueous solutions 
has been explained as due to its low porosity, and for this reason 
it is common to use more concentrated aqueous solutions in treat- 
ing it; as, for instance, in diazotizing and developing, than for 
the other fibers. 

One of the principal difficulties with the other rayons has been 
their low tensile strength when wet. It was at one time even diff- 
cult to piece-dye some of the rayons without damaging the fabric. 
However, in most instances this difficulty has been overcome to a 
large extent, but they are still not all that could be desired in this 
respect. A number of methods for waterproofing or lowering the 
water absorption of the older rayons have been proposed, in order 
to improve their wet strength. The “sthenose’’* process appears 
to have received the most publicity and has been stated to consist 
of a formaldehyde and lactic acid treatment of the yarn. While 


"See British Patent No. 25, 647 of 1906. 


46 ACETATE SICK 


the rayon is waterproof, it becomes more harsh and its dyeing 
properties are altered, as would be expected. Dr. Luft proposed a 
process based upon treating viscose rayon with aluminum acetate 
during the desulfurization. Very probably this treatment would 
also considerably alter its dyeing properties. 


C 
FIGURE II 


Showing Viscose (a), Celanese (b), Cuprammonium (c), and Tubize (d), 
Silk Fibers 


Courtesy Associated Knit Underwear Manufacturers of America 


Another idea along the same line is covered by British Patent 
No. 258,854, July 17, 1925, to L. Lilienfeld, which states that the 
tensile strength of viscose, cuprammonium, Chardonnet and ace- 
tate silks may be increased from 40 to 100 per cent by impregnat- 


GENERAL.PROPERTIES At 


ing the yarn in skeins or fabric with a solution of cellulose thioure- 
thane in which at least one hydrogen atom of the amino group is 
replaced by an alkyl radical, the solvent being subsequently re- 
moved. Suitable solvents include aqueous solutions of alkalies 
such as sodium hydroxide or ammonia, which of course would be 
unsuited for use on acetate silk, and volatile solvents such as 
pyridine. The rayon is preferably stretched during the treatment, 
as specified in British Patent No. 253,853, and the impregnated 
silk may: be rendered highly flexible by exposure to the vapors of 
a suitable organic solvent, such as pyridine, as described in Bri- 
tish Patent No. 231,806 and No. 248,994. 


Regain and Strength 


Normally, acetate silk contains less than 5 per cent of moisture 
(condition), and even when wet, it retains only about a third or a 
half as much water as the other rayons. This apparently accounts 
for its superior strength, as compared with the other rayons, when 
wet. Palmer! writes that whereas the older rayons retain about 
one third of their strength when wet, acetate silk is two thirds as 
strong wet as dry. When the acetate silk contains the same 
amount of water as the older rayons, it does not appear to be any 
stronger than the others. However, due to its low porosity and 
permeability, acetate takes up water rather slowly and to a smaller 
extent than the other rayons under the same conditions and there- 
fore retains a larger proportion of its dry strength, when wet, 
than the other rayons.? 


WET AND Dry STRENGTHS OF VARIOUS RAYONS 


Variety Titer Dry Strength Absolute Wet Relative Wet Strength 
Strength 3 
Glanzstoff 147.5 1.45 0.58 39.87 
Agfa 184.5 yey. 0.56 44.3 
Spinnerfaser A.G. 182. 1.47 0.66 44.9 
Acetatseide 134. | 0.88 0.43 48.9 


» Suchanck® states that if the wet and dry strength of acetate silk is 
compared with that of the other rayons on the basis of the relative loss 
of strength, or of the percentage loss of strength calculated on its dry 
strength, the supposed superiority of wet acetate silk over the other wet 
rayons is very slight. He gives the above table showing these figures, 
but does not state what variety of acetate silk was used in making the 
tests. Probably it was one of the Continental products. 


48 ACETATE. SIE 


Prof. Grimshaw? reports experiments which show that when 
Celanese is exposed to an atmospheric relative humidity of 84 per 
cent, the equilibrium regain is only 8.59 per cent; while under the 
same conditions cotton has 12.5 per cent of regain and viscose 


' FIGURE III 
True Silk Fibers 


Courtesy Associated Knit Underwear Manufacturers of Americu 


15.69 per cent. Under room conditions, wherein cotton had 6.8 
per cent of regain and viscose 9.52 per cent, Celanese had only 
3.57 per cent of regain. In other words it usually contains only - 
about one-third to one-half as much moisture as the other rayons. — 
Parker and Jackman? report that after drying the various textile — 
fibers for five days over phosphoric acid at 21° C. (70° F.), they 
ei q 


GENERAL PROPERTIES 49 


contained the following amounts of moisture: Celanese, 0.1 per 
cent ; viscose, 2.2 per cent; cotton, 0.8 per cent; linen, 1.0 per cent; 
normal and chlorinated wool, 2.0 per cent; silk 1.1 per cent. 
Celanese does not appear to reach equilibrium with the atmos- 
phere, from the dry condition, as rapidly as cotton, but more 
quickly than wool, silk, or viscose. 

Prof. Johnson* investigated the relative hygroscopic properties 
of the different rayons at various relative humidities. His results 
are shown in Table V. It is interesting to note that at low humidi- 
ties, Lustron appears to be more hygroscopic than Celanese, in the 
ratio of 1.0 to 0.89; while at higher humidities, Celanese is more 
hygroscopic, in the ratio of 1.17 to 1.0. 


TABLE V 


AVERAGE RESULTS OF TESTS UPON THE REGAIN OF RAYONS AT 15 
PER CENT (A), 68 To 61 PER CENT (B), AND 76 To 61 PER CENT (C), 


RELATIVE HUMIDITIES 


AH75°F.) B (70°F.) CAse 5) 


Nitro (Tubize), 150 denier 6.79 15.4 16.6 
Viscose, 300 denier 6.60 14.4 1575 
Cuprammonium, 120 denier 7.18 14.6 16. 

Celanese, 150 denier 1.91 6.87 7.74 
Lustron, 300 denier eae len 5.49 6.61 


Mercerized cotton a oo 8.24 


Hassac*! investigated the properties of six rayons in use about 
1900 and his results are given in Tables VI and XIX. The first 
three samples are nitro silk, a from Pris de Vaux, near Besancon; 
b from Fisme in Northern France; and c from Watson, England. 
Sample d is a collodion silk made by the Lehner process at Glatt- 
burgg, near Zurich; e a cuprammonium silk prepared by Pauly’s 


TABLE NO. VI 
PROPERTIES OF EARLY ARTIFICIAL SILKS, ABOuT 1900 


Number of 
Fibers per 1 
Moisture per cent Sq. mm. Tensile Strength Extension 
Variety Air-dry Saturated Wet Dry Wet Dry Per Cent 
True Silk 8.71 20.11 9710929571082 3720 37.0 VALS 
(a) Pris de Vaux 11.11 27.46 640 1,135 Dao, 12.0 8.0 
(b) Fismes 10.92 27512: 370 656 126 (pokes 11.6 
‘ Walston 11.32 28.94 683. 1620 1.0 22.73 7.9 
c) Lehner 10.45 26.45 413 1180 ine 16.9 7.5 
(e) Cuprammonium 9.20 23.08 742 1550 5 tas 19.1 12.5 
(f) Gelatin 13.98 45.56 265 945 Nil 6.6 3.8 


K 


50 AGEVATEH Sith 


process at Oberbruch, near Aachen; and f is a sample of Hummel’s 


gelatin silk. ) 
Parker and Jackman? investigated the strength of different 
materials by means of the Mullen bursting test. Wool, true silk, 


* 


FIGURE IV 


Cross-section of Lustron 
Courtesy Associated Knit Underwear Manufacturers of America 


viscose, and Celanese fabrics, both woven and knitted, showed a 
large and fairly regular fall in strength as the humidity increased, 
although when wetted, the loss with true silk was only half the loss 
with viscose, which was affected most. Celanese and wool showed 


GENERAL PROPERTIES 51 


losses intermediate between those of true silk and viscose. Cotton 
and mercerized cotton showed a slight increase in bursting strength 
with rising humidity, while linen was 25 per cent stronger wet 
than when dry. In all cases the change in strength on wetting 
appears to take place rapidly. Pieces tested immediately after 
wetting and those tested after soaking for two days gave the same 
strength. The strength changes are only temporary, all fabrics 
reverting approximately to their original strength when recon- 
ditioned at, say, 70 per cent relative humidity. 

Table VII gives a summary of their results. 


TABLE VII 
BURSTING STRENGTH OF FABrics (MULLEN TESTER) UNDER VARIOUS 
CONDITIONS? 
Wool Silk Jap Celanese Celanese Viscose 
Treatment Woven Knitted Silk Knitted Woven 
Seibea, 8 Ibs % lbs: % Iba %-. Ibs. % ibs. G 
Conditioned at 70% saueetoo © 87 100 77 100-51 100 66. 100 41 -100 


Rar and 21° C. 
Wet 21 ys) SF 65 (a 92 28 55 sien), ie 15 67 
Wet and hot, after boil- 


ing1ihr.indistilled water 19 50 49 56 55 Wipe 24 47 30 45 15 37 
Wet, after 45 hrs. in 
‘ol é sodium oleate at 


Wet and hot, after 1 hr. 
in 1.0% sodium oleate 
at 60°C. 18 47 —_——- 61 79 28 S)s) 38 58 15 2i 
Wet and hot, after 1 hr. 
in 1.0% sodium oleate, 
boiling 10 26 —_——- 56 73 24 47 29 44 15 37 
Wet and hot, after 1 hr. 
in 1.0% sodium oleate, 
boiling 1355. 35 —— Suir. Ths} 29 S77 35 53 16 39 


744 Some 50869 «69 OOF 2S aos oO SOmey Lomo 7) 


TABLE VIII 


STRENGTH OF 150 DENIER Du PONT VISCOSE AND CELANESE RAYONS 
IN 120 YARD LENGTH SKEINS ON A SCOTT TESTER? 


Moisture corresponding to a Break per Skein in Pounds 

Cotton Regain of Du Pont Viscose Celanese 
6.7 per cent 59.3 Bo. / 
7.7 per cent 60.0 61.0 
12.5 per cent S510 49 .3 
13 


.7 per cent 55.0 ‘49.7 


52 ACETAT Besiiar 


TABLE IX 
COMPARATIVE STRENGTH OF VARIOUS RAYons® 


Tensile Strength 


Dry Wet Extension 
Chardonnet 0.75 to 1.4 0.25 to 0.6 7.5 to 16.0% 
Cuprammonium 1.0) to1:35 0.35 to 0255 14.0 to 18.0% 
Acetate ee Ae | 0.7 18.0% 
Viscose 122 fo eo 0.45 to 0.7 11.0 to 22.0% 
Natural silk a 2.0 21.0 
TABLE X 


MOISTURE IN DIFFERENT VARIETIES OF RAYON? 


Nitro Nitro Acetate 
Raw Rayon, Rayon, Rayon, 
Sik Process A Process B (Celanese) 
Relative Per Cent’ Per Cent of Per Cent of Per Cent of 
Temperature Humidity of Moisture Moisture Motsture 
Lae °F. Per Cent Moisture (110 denter) (110 denier) (175 denier) 
14.5 58 62 9.834 10.150 10.346 5.134 
14.5 58 72 10.647 10.729 10.862 5.626 
20.0 68 60 9.460 9.956 9.457 4.600 
18.0 64 65 . 9.834 10.248 9.773 4.921 
19.0 66 65 7.148 10.334 9.825 4.957 
$52 0nb OO 72 8.139 11.016 10.605 5.556 
4875 765 72 8.626 11456 10.708 5.591 
20.5 69 70 8.809 11.068 10.708 5.486 
19.0 66 a3 8.931 11.347 10.913 5.696 
20.0 68 75 9.007 11.536 11.117 5.905 
TABLE XI 
WET STRENGTH OF WET FIBERS, AS A PERCENTAGE OF THEIR DRY 
STRENGTH® 
Cotton 110-120 per cent 
Wool 80- 90 per cent 
Silk (true) 75- 85 per cent 
Acetate silk 65- 70 per cent 
Cuprammonium silk 50- 60 per cent 
Viscose silk 45- 55 per cent 


Nitro silk 30- 40 per cent 


GENERAL PROPERTIES 53 


TABLE XII 


ABSOLUTE RESISTANCE IN KILOGRAMS PER SGUARE METER OF VARIOUS 
FIBERS AND RaAyons?® 


Dry Thread Wet Thread 


Raw true silk 50.0 41.0 
Weighted true silk 20.0 15.0 
Collodion silk 17.0 4.3 
Cuprammonium silk 1971 325 
Viscose silk y Ales So 
Cotton 1125 18.6 
Diameters of Various Fibers 

Wool 0.0005 to 0.002 inch 
Cotton 0.0004 to 0.001 inch 
Silk about 0.0007 inch 

Rayon about 0.0018 inch 

TABLE XIII 


STRENGTH AND ELASTICITY OF EARLY Rayons (ABOUT 1900) 
(On Basts of a Standard 100 Denier Thread) 


Breaking Elasticity 


Type Weight Per Cent 
Nitro by Chardonnet process (undenitrated) 150 23 
Same, after denitrating and drying 110 8 
Same, after denitrating but undried Jas — 
Nitro by Bronnert process (undenitrated) 125 28 
Same, after denitrating and drying bie 13 
Same, after denitrating but undried 32 — 
Natural silk 300 18 

TABLE XIV 


PROPERTIES OF RHODIASETA BRAND ACETATE SILK, 75 DENIER YARN, 
200 TurNs PER METER 


Dry Wet 
Tensile strength in gr. per denier 1:25 to.1.35 O78 
Elongation in per cent ERM Kee ete) 35 


Real elasticity, per cent 2.6 


It has recently been reported*? that after immersion in water 
and squeezing under comparable conditions, fully saponified ace- 
tate silk retained 74 per cent of water, while the partially saponified 
fiber, such as that used in printing, retained only 50 per cent, and 
the unsaponified acetate silk (variety not stated) only 35 per cent 
of water. 


54 ACETATE SILK 


Elasticity 


Dr. Luft® states that there is a rather constant ratio between 
tenacity and elongation in relation to the moisture content of 
rayon. Rayon (except acetate) loses strength when wet because 
it readily absorbs about three parts of water to one part of dry 


FIGURE V 


Cross-section of Celanese 
Courtesy Associated Knit Underwear Manufacturers of America 


rayon, increasing in volume at the same time by about 40 per 
cent. When dried, it contracts and regains its previous volume 
and tensile strength. He explains the hygroscopic capacity of the 
older rayons as due to their capillary structure. 


GENERAL PROPERTIES 55 


ABER XV 
TENSILE STRENGTH AND ELONGATION OF SILK AND RAYONS? 


Tenacity in 


Grams per Denier Per Cent 
Dry Wet Elongation 
Natural silk 2 2.0 2120 
Cuprammonium silk 1.3 0.5 125.5 
Nitro silk 1.48 O73! 15.5 
Viscose silk WS fe 0775 20.0 
TABLE XVI 


LOWER LIMIT OF STRENGTH AND STRETCH FOR THE BEST GRADES OF 
RAW SILK AND TYPEs OF RAYON? 


Strength in Stretch in 
Grams Per Denier Per Cent Elongation 

Raw silk 3.50 up 20 up 
Regenerated rayon from cotton 

linters 1.70 up 20 up 
Regenerated rayon from wood 

pulp 1.50 up 20 up 
Acetate silk 1.30 up 30 up 

TABLE XVII 


STRENGTH AND STRETCH OF VARIOUS RAYONS 


Strength in Stretch in 
Number of Denier Grams Per Per Cent 
Threads Size Denier Elongation 


Regenerated Cellulose Rayon from Wood Pulp 
American I, Factory No. 1 


grade A 100 150 1.56 Zo 
American II, Factory No. 1, 

Grade A 200 150 1.54 28.5 
American III, Factory No. 2, 

best grade A 200 150 1.60 24.5 
American IV, Factory No. 3, 

best grade A 200 150 1.56 Za ald 
European, grade not known, 200 150 1.48 20.0 
European, grade C 100 120 1.42 23.0 
Regenerated Cellulose Rayon from Cotton Linters 
European, grade not known, 200 80 1.63 IN pe 
European, grade not known, 100 300 1.56 20.0 
American Factory No. 1, best 

grades 200 150 1.76 20.0 
American Factory No. 2, best 200 150 1.85 22.0 

grades 
Acetate Rayon 
European 200 150 1.30 29.0 

0 


European 50 300 1.20 an fen 


56 ACETATE Sits 


TABLE XVIII 
SHOWING THE AREA, TENSILE STRENGTH, AND ELASTICITY OF THE 
VARIOUS Rayons!? 


Mean Area Tensile Strength  Elasticityin 
of Cross Sec- inGrams, Calc. Per Cent Calc. 
tion of Fiberin forl00Sq.in. for 100 Sq. in. 


Sq. in. Cross Sectional Cross Sectional 
Type Area Area 

Dry Wet Dry Wet 

Degummed Italian silk 109 Ve Ge Fie 13.22.15.9 
Cuprammonium 105 K I EES ie 129 ees 
Viscose I 387 SDs 3.0 2.0 
Viscose IT 596 3.bivakee ar Zee 
Viscose III 498 2 ee 2.8 Bi | 
Chardonnet T I 584 379 eaae 5 ee 2.6 
Chardonnet T 2 424 2 Ti eee aga) 2.4 
Chardonnet T 3 728 2:05 oe lee 2.6 1.7 
Chardonnet S. KZ 225 3,3. 2h 3.6 3.2 
1.3 Slee 6.1 5.4 


Acetate 447 


According to Oppe and Gotze,! viscose silk increases in length 
about 0.6 to 0.8 per cent with an increase in the humidity of the 
atmosphere from dry air to 3.5 per cent relative humidity. An 
increase in the relative humidity from dry air to 83 per cent 
relative humidity gives an increase of from 1.1 to 1.5 per cent in 
the length of viscose. It is interesting to note that, while acetate 
silk absorbs a far smaller amount of moisture under the same 
conditions, it does not show any notable variations in length, at 
the various humidities, from the other varieties of rayon. 


Alkalies and Acids 

The resistance towards alkalies varies with the product, Celanese 
being considerably more sensitive than Lustron, but neither should 
be allowed to come into contact with strongly alkaline solutions, 
especially when hot, except under special conditions, otherwise 
both become blind, curly and wool-like. However, in spite of this, 
fabrics containing either Lustron or Celanese may be mercerized 
under the proper conditions. 

For example, British Patent No. 210,484, October 5, 1922, to 
W. Marshall‘ states that cotton yarns in mixed fabrics containing 


*United States Patent No. 1,511,741, October 14, 1924, to W. Marshall 
covers the same process, which gives excellent results on piece goods, etc. 
The dyeing properties of the acetate silk are almost unaffected, except 
that it acquires more affinity for certain direct dyes. The same process may 
also be used for the production of crepe effects by mercerization without 
tension. 


GENERAL PROPERTIES 57 


acetate silk and unmercerized or incompletely mercerized cotton 
may be mercerized by treatment with a sodium hydroxide solution 
of 1.24 to 1.30 specific gravity at a temperature below 15° C. (59° 
F,). The fabric should then be squeezed between rollers, stretched, 


FIGURE VI 


Cross-section of Rhodiaseta 
Courtesy Societe pour la Fabrication de la Soie “Rhodiaseta ” 


washed, treated with dilute acid, and washed until neutral. During 
this treatment the acetate silk does not lose its luster or shrink, the 
loss in weight is very slight, and its dyeing properties are not 
materially affected. In order to avoid a crepe effect, the fabric 
should be mercerized under tension. This or a similar. process 
is now in use in several plants. 


58 ACH TAs ees rte 


While the above patent probably applies particularly to Celanese, 
Lustron in combination with cotton will also withstand the mer- 
cerizing process on the usual mercerizing range with sodium 
hydroxide solution of 13 to 15 per cent strength at temperatures 
below 5° C. (40° F.) without loss of its cross-dyeing properties, 
and with proper care will even withstand the action of a 35 per 
cent sodium hydroxide solution at 15° C. (60° F.) for a short 
time. After mercerizing, the union should be rinsed as before, 
and the remaining alkali neutralized with dilute acetic acid, never 
with mineral acids. The dilute acid remaining in the fabric may 
be neutralized with sodium bicarbonate if the goods are not to be 
used immediately. In case the mercerizing is not done on a 
machine, contact with the mercerizing solution should not exceed 
45 seconds. 

Towards mineral acids, the resistance of acetate silk is not as 
great as that of the older rayons. Little!* states that acid hydrolysis 
affects acetate silk in much the same manner, in the initial stages, 
as saponification (alkaline hydrolysis) ; but upon being carried to 
the extreme, there is an actual disintegration of the fiber very 
similar to that which occurs in the case of cotton when sulfuric 
acid is left in it. This of course means complete destruction of 
its textile properties. 

The manufacturers of Celanese warn against the use of alkalies, 
but state that it will withstand the usual alkaline emulsion finish, 
or an acid finish containing 2 cubic centimeters per liter of formic 
acid. The Lustron Company advise against the use of sulfuric 
acid in any process on their product, suggesting the substitution 
of formic or acetic acid. They also state that no matter what the 
dyeing process has been, the last wash water should contain about 
0.5 ounce of sodium bicarbonate per gallon of water, and the goods 
should be wrung and dried without further rinsing. Finishing 
materials for Lustron should be slightly on the alkaline side. In 
the presence of strong oxidizing agents, acetate silk forms oxy- 
cellulose. 

Prof. Johnson? found that upon boiling the four types of rayon 
for fifteen minutes with 15 per cent of sodium hydroxide, wash- 


* This probably applies particularly to Lustron which is more sensitive to 
mineral acids than Celanese. 


GENERAL PROPERTIES 59 


ing thoroughly, neutralizing in very dilute acetic acid, and wash- 
ing acid free with water, nitro silk was disintegrated ; but acetate 
and viscose silks held up better. Upon treating 150 or 300 denier 
rayon yarns for 15 minutes in a 5 per cent solution of sodium 
hydroxide at 82 to 93° C. (180 to 200° F.), then washing, neutral- 


FIGURE VII 


Cross-section of Cuprammonium Silk 
Courtesy Associated Knit Underwear Manufacturers of America 


izing, and washing as above, finally rinsing in 95 per cent alcohol, 
then in ether, and drying at 110° C., the various rayons lost weight 
as follows: nitro 8.41 per cent, viscose 2.26 per cent, cupram- 
monium 3.96 per cent, Celanese 53.0 per cent, and Lustron 64.0 
per cent. The Lustron and Celanese yarns were largely reduced 


60 ACETATE SILK 


to a slimy mass. While wool was completely dissolved in from 3 
to 5 minutes by the above treatment, raw true silk and Tussah 
silk did not completely dissolve in 5 minutes. 


Luster and Blinding 


In his report upon the rayons in use about 1900, Hassac** states 
that the Pris de Vaux, Fismes, and Lehner samples (see Table 
VI) were very similar in appearance and more lustrous than true 
silk. The Walston sample was rough and hairy, resembling mo- 
hair rather than silk. The cuprammonium silk resembled the 
Pris de Vaux and Fismes samples, with a higher luster, and the 
feel of true silk when in the piece. When wet out with water, 
the Pris de Vaux, Walston, and Fismes samples under the mi- 
croscope at 150 diameters appear very similar, the last named 
being more deeply grooved. The Pris de Vaux had the most 
symmetrical outline in cross section, and the Fismes the least 
symmetrical. The Lehner was characterized by deep longitudinal 
grooves, and by small air bubbles, its cross section being very 
irregular. The cuprammonium had fine longitudinal grooves, and 
minute transverse lines in the center of the fiber cross section. 
Its cross section was regular, approaching a circle or ellipse. The 
gelatin silk was almost circular in outline and free from grooves 
and bubbles, the fracture even and the thickness constant. In 
polarized light the gelatin silk was singly refractive, while the 
others were doubly refractive. The cuprammonium showed uni- 
form interference colors over considerable lengths of fiber. In 
the Pris de Vaux, Fismes, Walston, and Lehner samples, the 
colors varied greatly owing to the irregular thickness of the fibers. 

Dr. Luft® describes the luster of the various rayons as follows: 
nitro is shiny and cuprammonium glassy, while viscose and acetate 
are silvery and more in the nature of true silk. Cuprammonium 
silk is generally more milky than viscose, but the latter also has a 
milky appearance at times. The feel of rayon is similar to true 
silk but slightly colder and harsher to the touch. The scroop of 
natural silk may be imitated on rayon by an acid finishing process. 
Acetate silk does not lose its sheen or silky feel on washing, or 
turn yellow with age, sunlight, washing, wear, or perspiration. It 


GENERAL PROPERTIES 61 


drapes well and Celanese is stated to be more regular in denier 
than any other variety of commercial rayon. 

The loss of luster by Celanese and related acetate silks (but not 
Lustron) when overheated in the presence of water vapor or in 
most aqueous solutions, especially in the presence of alkalies, has 


FIGURE VIII 


Cross-sectoin of Tubize Silk 
Courtesy Associated Knit Underwear Manufacturers of America 


been mentioned quite frequently in the foregoing pages. This 
phenomenon is also known as “blinding’’ and may be due to any 
one of a number of causes, such as an acid-bichromate treatment,® 
as in mordanting wool; the action of certain metallic salts, such as 
the chlorides of copper, calcium, magnesium, etc.; or improper 


62 ACETAL ER Slik 


handling during the development of certain diazotized colors on 
the fiber, in which case the coloring matter appears to be pre- 
cipitated near the surface of the fiber. 

Very probably this blinding is due to a loss of acetate groups 
by the cellulose acetate, possibly due to the hydrolysis of the ester 
at the higher temperature. This theory is supported by Green- 
halgh1* who states that it is not due to physical causes, and by the 
fact that this blind fiber may be relustered by an appropriate treat- 
ment with an acetic acid solution of suitable strength.! This effect 
is probably due to dehydration in the presence of a solvent of 
higher boiling point than water. It may be that the superior hot 
water resistance of Lustron is mainly due to two cases; i.e., the 
presence of a larger proportion of combined acetic acid groups, so 
that a larger number may be removed before the luster is im- 
paired, and to the presence of neutralized sulfuric acid group, 
which Caille’® reports greatly increases the resistance of the fiber 
to hydrolysis in hot water. 

As may be expected, any operation on acetate silk which inter- 
feres with, or impairs its luster, has the tendency to reduce the 
brilliancy of the color of the dyed fiber. In most cases there 
appears to be a definite relation between the luster of the fiber 
and the brilliancy of the dyed shade and very probably if we were 
able to apply to cotton the dyes giving the most brilliant shades on 
acetate silk, the resulting brilliancy of shade would not be at all the 
same. 


Temperature 


The resistance of Lustron to dry heat!” is similar to that of vis- 
cose, true silk, or cotton, either at high temperatures for short 
periods, or low tenrperatures for a longer time. Wherever pos- 
sible it should be dried at a low temperature. At temperatures 
above about 225° F., Celanese becomes glazed and brittle. As 
previously mentioned, at temperatures above about 85° C. (185° 


* Also see other methods of relustering acetate silk in Chapter XXXVIII. 

® United States Patent No. 1,607,474, November 16, 1926, to H. S. Mork 
of the Lustron Company states that cellulose acetate and acetate silk are 
rendered more stable to the action of heat, carbonization being inhibited, 
by incorporation, before or during the manufacturing process, of 0.5 to 2.0 
per cent of the potassium or sodium salt of acetic, oleic, salicylic, benzoic, 
or other suitable organic acid. 


: 


Benth AL PROPERTIES 63 


_F.), in the presence of water, as in dyeing, Celanese and Rhodi- 
aseta become “blind” unless special precautions are taken to 
prevent this, such as the presence of certain suitable inorganic 
salts." On treating Celane$e with boiling water, it shrinks, becomes 
curly and wool-like, and the luster is completely destroyed in a 


FIGURE IX 


Cross-section Du Pont Silk 
Courtesy Associated Knit Underwear Manufacturers of America 


few minutes. Hot ironing with a damp cloth also injures Celan- 
ese, but dry steaming for say 15 minutes, without pressure, does 
not seriously damage it and this process is sometimes used in 


» See British Patents No. 206,113 and No. 246,879. 


64 ACETATE Sian 


printing Celanese fabrics. On the other hand, Lustron can be 
treated in boiling water without affecting its luster or general 
appearance. This enables it to go through a regular silk boil-off 
and dyeing at boiling temperatures without alteration of its ap- — 
pearance. | 
Flammability 

According to a recent article in the Technical News Bulletin, 
tests made at the United States Bureau of Standards indicate that 
cuprammonium silk is the only rayon which ignites more easily 
than cotton, but this difference is very slight. Viscose ignites at — 
approximately the same point as cotton, while the nitro is less — 
susceptible to ignition than cotton. Acetate silk is even less sus- 
ceptible to ignition than the nitro. 


Microbiological and Electrical Resistance 


Thaysen and Bunker!” investigated the resistance of the four 
commercial varieties of rayon to certain cellulose destructive organ- 
isms. ‘Tests were made (1) in an anaerobic medium, (2) by bury- 
ing in garden soil, and (3) by submerging in sea water. Acetate — 
silk was found to be the most resistant. The resistance of the 
older rayons varied in the following order: nitro, viscose, and 
cuprammonium. | 

The unusually high resistance®® of cellulose triacetate to hydrol- 
ysis by enzymes is lost when the ester is saponified, and the re- 


generated cellulose is hydrolyzed about 35 timés more than the ~ 


normal unacetylated cellulose by the enzyme of snails. 

The electrical resistance of acetate silk is greater than that of 
any other known fiber, especially in a damp atmosphere, and for 
this reason it is rapidly displacing real silk for electrical insulating 
purposes in many places. | 


Specific Gravity 
Chardonnet in 1889 gave the specific gravity of rayon prepared 
from collodion (nitro silk) as 1.49, raw silk 1.66, and boiled-off — 
silk as 1.43. Herzog’® gives the specific gravity of Chardonnet — 
silk as 18 per cent higher than that of true silk, which on a basis 
of 1.48 for true silk, would be about 1.62. Silberman?® states that — 


Gey ekAlL PROPERTIES 65 


Lehner’s silk (nitro) should be 7 to 8 per cent heavier than true 
silk, (1.43 plus 8 per cent) or 1.545 sp. gr. The specific gravity of 
cuprammonium silk is greater than that of nitro or viscose. Has- 
sack,?? and Saget and Suevern?! report the specific gravity of 


FIGURE X 
Cross-section Industrial Fiber 
Courtesy Associated Knit Underwear Manufacturers of America 

natural silk as 1.36, and that of the rayons as 1.50 to 1.53. Wor- 
den”? gives the specific gravity of acetate silk, probably Lustron, 
at 1.25. The specific gravity of Rhodiaseta is 1.27. Luft® gives 
the gravity of cellulose rayon (variety not stated but probably 
viscose) as 1.5, and that of true silk as 1.4. 


66 ACI TAME Sate 


TABLE XIX 
SPECIFIC GRAVITY OF DIFFERENT RAYONS OF ABOUT 1900 
Natural sill. 5.0... os dn dg ooo wevleletw piece a peer e ee ee nae etn 1.36 
Pris de Vaux silk (Chardonnet): 2.2.5... . see 1.52 
Fismes silk. .. 5... 05.6 0 0.0 s > bo esis 4 0 ne -00dne Geyer nna ieee naan 1,52 
Walston silk. .... 0. ce cc ow vee e's oo bine ego eel eiiet Gees nea enn 1.53 
Glattbrugg-silk (Lehner)... 2.0... <.y + 20s ieee 1.5% 
Glanzstoff silk... ... 0.20 eae 6 cco sosleve «6 5islaes apne eure meen 1.50 


Gelatin silk. 2.0.0.0. 0006000 oe ee bes ome 4s crete eLsne a eeeeee sn 1-55 


Refractive Index! 


The refractive index of acetate silk, as compared with the other 
rayons and natural fibers, is low. This applies to the older 
chloroform soluble (primary) type as well as the newer acetone 
soluble (secondary) variety. Herzog?® reported the refractive in- 
dex of acetate silk as 1.474 to 1.479, with sodium light. Judging 
from the date, this was undoubtedly a primary acetate. Recent 
work by the author indicates that this figure checks fairly well for 
both Lustron and Celanese of today. Acetate silk is more trans- 
parent to ultraviolet light than any other fiber. 


Structure 


Herzog, who has made a considerable investigation on the struc- 
ture of various materials by means of X-rays, in a joint paper 
with Jancke,** states that from their experiments with X-rays they 
believe that in plant fibers the cellulose is present in crystalline 
form, dispersed symmetrically with respect to the axis of the fiber. 
Natural silk also shows the symmetrical crystalline structure. The 
rayons, with the exception of acetate, consist of an irregular felted 
mass of crystalline fragments of unchanged cellulose. Acetate 
silk is amorphous and consists of a mixture in which the cellulose 
acetate has undergone considerable degradation. Animal hair 
is also amorphous and probably consists of two or more substances, 
while starch and pure fats are crystalline. 

Ott?’ contradicts the statements of Herzog and others that the 
X-ray diagrams of cellulose triacetate show it to be amorphous. 
His diagrams show a crystalline structure but the interference 


* Also see Identification of Rayons. 


SeNe RAL PROPERTIES 67 


bands are rather blurred, owing to the minute character of the 
crystals, and their low intensity may account for their having been 
overlooked previously. Probably this fine crystalline structure ex- 
plains the low porosity of acetate silk. 

According to Hess, Schultze and Messmer,”® Bayer’s “‘Cellite, 


FIGURE XI 


Cross-section Viscose Silk. 
Courtesy Associated Knit Underwear Manufacturers of America 


which is soluble in acetone but insoluble in chloroform, and is pre- 
pared by the partial hydrolysis of cellulose triacetate with sulfuric 
and acetic acids, as in German Patent No. 252,706, consists of a 


} Herzog™ reports that both cellulose acetate and nitrate have a rhom- 
bic structure. 


68 ACETATE Seis 


mixture of cellulose triacetate and isomeric diacetates in the ratio 
of 1 to 4, together with dextrose and cellobiose. After about six 
precipitations from benzene-alcohol, the mixture of tri- and di- 
acetates shows signs of crystallization, and well defined crystals 


FIGURE XII 


Cross-section of True Silk 
Courtesy Associated Knit Underwear Manufacturers of America 


are eventually obtained. These are stable only in contact with the 
solvent and become amorphous when dry. Like the triacetate 
crystals, they show no X-ray line spectrum. The rotary power 
curves indicate that the crystalline acetate is derived from chemi- 


GENERAL PROPERTIES 69 


cally intact cellulose, and it is impossible to separate the cellulose 
into isomerides by prolonged fraction crystallization or chloroform 
extraction of the di- and triacetates. 

Microscopic examination?’ of the cross section of viscose silk 
shows corrugations similar to the bark of a tree and the individual 
fibers interlock each other due to these corrugations, the result 


Eo. EC TIONS or ARTIFICIAL anno REAL SILK. 
VISCOSE 
pag 


750 MAGNIFICATIONS) 


Q 


FIGURE XIII 


A Comparison of the Cross-section of the Various Rayons. Under Acetate 
ilk, No. I is Lustron and No. II is Celanese 
Courtesy Associated Knit Underwear Manufacturers of America 


being greater strength and covering power. The cross section of 
acetate (variety not stated) and cuprammonium silks show no 
corrugations, the former being more oval, and the latter one round 
and of uniform diameter. Nitro silk is more oval than viscose 
and shows only slight corrugations. Very probably the micro- 


70 ACETAL ER site 


scopic cross section of any one kind of rayon will vary considerably 
with the differences in details of manufacturing methods, such as 
the dry spinning and wet precipitation methods used in the manu- 
facture of acetate silk. The accompanying figures show the micro- 
scopic characteristics of the various rayons. 


References 


*C. W. Palmer, Textile Recorder 42, No. 500, 90 (1924). 

* A. H. Grimshaw, Textile World 67, 1397-9 (1925). 

®R. G. Parker and D. N. Jackman, J. Soc. Chem. Ind. 45, 47-54 T (1926). 

*A. K. Johnson, American Dyestuff Reporter 14, 875-8 (1925). 

° Hassak, Oesterreische Chemtker Zeitung, 1900. 

Swe Stokes, J. Soc. Dyers and Colourists 38, 51 ee 

TOW tS Edwards, Textile World 68, 1792-4 (1925). 

SJ. Obermiller, Z angew. Chem. 39, 46-51 (1926), aa Melliand’s Tex- 
tilber. 6, 818-9 (19 25); 

°M. G. Luft, Textile World 69, 319-21 (1926). 

© Faserst und Spinnpfi., 1923, p. 31. 

™ Oppe and Gotze, Textilber. a 850-4 (1925). 

*R. Little, American Dyestuff Reporter 13, 6 (1924). 

PNK Johnson, American Dyestuff Reporter 14, See 75 (1925). 

“E. Greenhalgh, Dyer and Calico Printer 55, 27 (1926). 

* EF. Greenhalgh, Dyer and Calico Printer 55, 190 (1926). 

1% A. Caille, Chim. et Ind. 13, 11-13 (1925). 

gil Oe Thaysen and H. J. Bunker, Biochem. J. 19, 1088-94 (1925). 

8°A. Herzog, La Faeber-Zeitung de Lehner, 1894 and 1895, pp. 49-50. 

9 Silberman, “Die Seide,’ Vol. II, 1897, p. 148. 

a 8 Hassack, Z. angew. Chem. 13, 89 (1900). 

** Saget and Suevern, Bull. Soc. d’Encouragement, 1906, p. 540. 

tha C. Worden, “Technology of Cellulose Esters,’ Vol. VIII, 1916, p. 
2830. 

* A. Herzog, Z. Farb. Text. Chem. 3, 259-60 (1904). 

*R. O. Herzog and W. Jancke, Umschau 25, 53-4 (1921). 

*®E. Ott, Helv. Chim. Acta. 9, 378-9 (1926). 

a) ty, Hess, G. Schultze and E. Messmer, Annalen 444, 266-87 (1925). 

7M. G. Luft, Rayon J. 1, No. 3, 19-25 (1926). 

*7'W. Garner, J. Soc: Dyers and Colourists 42, 267 (1926). 

a Gi Moncada, Atti. I. Congr. naz. Chim. pur. appl. (1923), pgs. 300-3. 

*° Suchanck, Silk J. 3, No: 27; 57-60 (19263; 

maa Hassac, Oesterr. Chem. Z. 3, 235, 267 and 297 (1900). 

2 A. Schneevoigt, Melliand’s Textilber. 7, 354 (1926). 

*P. Karrer, Melliand’s Textilber. 7, 23-4 (1926). 

ee. Herzog, Helv. Chim. Acta. 9, 631-3, 798-9 (1926). 


SOAPLER:V. 
ion RICATION OF THE RAYONS 


A Discussion of the Various Properties and Tests Used in 
Identifying the Different Rayons 


BEFORE attempting to dye or, in fact, to conduct any other pro- 
cess on rayon or materials containing it, the dyer should know 
exactly the variety of rayon he has to handle. As mentioned be- 
fore, each different process of rayon manufacture produces a 
product which differs in some points from all other rayons and 
fibers. In the case of acetate silk, the product differs widely from 
all other commercial fibers in many ways. These very differences 
form the basis of the many ways of identifying the products of 
the various methods of rayon manufacture. Of course the point 
which is of major interest to the dyer is their differences in dyeing 
properties, such as dyestuff affinity, fastness, exhaustion, ete. 
Most dyers are so familiar with the older rayons that once they are 
identified, they know how to handle them. 

While a number of methods for the detection of rayon, as well 
as the identification of the particular variety present, have ap- 
peared in the literature, no one of these methods is applicable in 
every case to give the full details usually necessary to the dyer. 
The differences between the rayons on one hand, and true silk 
or mercerized cotton on the other, show up readily under the 
microscope, while the differences between rayon, cotton, linen, 
wool, etc., are plainly visible to the eye alone. However, it is 
difficult to identify the variety of rayon even under the micro- 
scope, which is not always available, so that chemical tests are 
also necessary. ‘The methods of detecting mercerized cotton, as 
well as estimating the degree of mercerization, will be dealt with 
in another chapter. 

Solubility Tests 

One of the simplest and easiest tests of individual fibers for 

acetate silk (Lustron,* Celanese and Rhodiaseta) is its solubility 


* While Celanese and Rhodiaseta dissolve completely in acetone, Lus- 
tron does not, but is soluble in chloroform, whereas Celanese and ‘Rhodi- 
aseta are not completely soluble in chloroform. 


71 


72 ACETATE Sia. 


in acetone. Warming hastens the solution, although they are also 
soluble cold within a short time. The fact that this method may 
be used upon either white or properly dyed acetate silk gives it a 
considerable advantage over the colorimetric tests. However, if 
the acetate silk has been saponified in dyeing or otherwise, it 
will not be completely soluble in acetone. But if the acetone sol- 
ution is evaporated, a film of cellulose acetate will remain, showing 
the presence of this compound. . 

It is also more or less soluble in warm 65 per cent or stronger 
acetic acid, particularly glacial acetic acid. The older regenerated 
cellulose rayons are not soluble in either acetone or acetic acid. 
It has been shown by Prof. Johnson! that there is some difference 
in the solubility of Lustron and Celanese in acetic acid. Near the 
boil, 30 cubic centimeters of 50 per cent acetic acid will dissolve 
0.05 gram of Celanese, while under the same conditions, it requires 
the same amount of 65 per cent acetic acid to dissolve Lustron.” 
Furthermore, upon pouring the 30 cubic centimeters of acid con- 
taining the Celanese into 15 cubic centimeters of water, a bulky 
Opaque mass is obtained which soon forms a flocculent sediment. 
Upon diluting the Lustron solution in a similar manner, only a 
slight opaqueness and some evidence of a translucent sediment are 
obtained. Where this test is made upon white acetate silk, the 
precipitate is white, but where the colored fiber is used i in testing, 
the precipitate is frequently colored. ? 

Acetate silks prepared from the older primary cellulose acetates 
are soluble in chloroform, while the later secondary cellulose acetate 
silks are only more or less plastic in chloroform alone, but are 
soluble in acetone. While Lustron is soluble in chloroform, Cela- 
nese only forms a jelly in this solvent and not a complete solution.’® 
Both varieties are soluble in glacial acetic acid, as well as more 
slowly in cold concentrated sulfuric acid. Acetate silk is soluble 
in tetrachlorethane and alcohol while the other rayons are not. 
Undenitrated Chardonnet rayon is soluble in cold amyl acetate. 
The solubility of acetate silk in other solvents is discussed further 
in Chapter ITI. 


> This is not the limit of solubility but is merely used for the purpose of 
this test and indicates the difference in the strength of an} required to 
dissolve the two varieties. 


TOE NTIFICATION OF RAYONS 73 


| Ammoniacal Copper Oxide Solution 

Acetate silk is swelled by, but is not soluble in, ammoniacal 
copper oxide solution (Schweitzer’s reagent), while the older 
rayons swell and dissolve, as also does fibroin (true silk). This 
reagent should be freshly prepared by dissolving 5 grams of cop- 
per sulfate crystals in 100 cubic centimeters of boiling water and 
adding sodium hydroxide solution until the precipitation is com- 
plete. Wash the precipitated copper hydroxide free of alkali and 
dissolve it in the least possible quantity of concentrated ammonium 
hydroxide solution. It is best preserved away from light. 


Chromic Acid 
- A half-saturated solution of chromic acid dissolves true silk 
slowly, and the older rayons in the cold, while acetate silk only 
swells and is not dissolved. This reagent is prepared by mixing po- 
tassitim bichromate with an excess of sulfuric acid. Crystals of 
chromic acid separate. These are removed and dissolved in water to 
give a saturated solution, which is diluted with an equal volume of 
water for use. 
‘oy Water and Alkali Tests 

Acetate silk does not swell in water, while all other rayons are 
turgoids and swell to some extent. Some of the recently proposed 
treatments for preserving the strength of the older rayons when 
wet may affect this swelling of the older rayons to some as yet 
unknown degree. The older rayons also lose a larger proportion 
of their dry strength when wet than does acetate silk. The ace- 
tate silks do not withstand the action of hot sodium hydroxide or 
other strongly alkaline solutions, in which they lose luster, as de- 
scribed in Chapter IV. The other rayons withstand this treatment 
better than acetate. They all swell to some extent, but none dis- 
solve, so that this test will readily serve to distinguish the rayons 
from true silk and wool. 


The Burning Test 
Another very simple test is the burning test which has been 
widely recommended for distinguishing the acetate silks from all 
other fibers. In making this test the fibers should be rolled into 
a tight little ball or wad and placed near the flame without touching 
it. With sufficient heat the acetate silk appears to melt rather than 


74 ACETATE Siar 


burn, in somewhat the same manner as sugar, forming a black 
globule which precedes the small flame down the thread. Upon ex- 
tinguishing the flame, the small lump on the acetate silk is rather 
hard. 

Cotton burns with a flash,”! little odor and almost no ash. Nitro, 
viscose and cuprammonium silks readily burn, like cotton, without 
melting, and leave almost no ash, which is soft. Vegetable fibers 
sometimes leave a slight ash in the form of the thread. The smoke 
has the odor of burning paper and turns moistened blue litmus 
paper red. 

Wool and silk are readily distinguished from the natural and 


artificial cellulose fibers, such as cotton, linen, rayon, etc., in the — 


burning test. The animal fibers leave a shining, tumefied, diff- 
cultly combustible cinder, which leaves considerable ash when com- 
pletely burned. The smoke has the characteristic odor of all 
burning nitrogenous animal matter, and turns moistened red lit- 
mus paper blue. It also turns tumeric paper brown. Wool and 
silk may also be distinguished from the rayons and vegetable 
fibers by the yellow color developed when steeped in either nitric 
or picric acid solution, the cellulosic fibers remaining white. 
According to Clayton? when a heavy cord of Celanese is placed 
near, but not in, a Bunsen burner flame, as the temperature rises 
the color of the fiber changes from white to yellow and yellowish- 
brown, finally becoming brittle, almost like a stick of sugar which 
has been heated to its melting point and allowed to cool. When in 
direct contact with the flame a slow burning action occurs with 
the formation of a black molten pellicle at the burning end. More 
or less charred globules may fall from the end of the burning 
Celanese yarn, especially if it is held intermittently in a vertical 
plane over the burner. He states that when cellulose acetate is 
heated in the air, it is gradually converted into a semi-liquid phase 
(possibly slightly beyond the point at which decomposition begins) 
and further heating causes its more or less complete decomposition. 
Cotton and the other rayons do not pass through a liquid phase 
upon heating in the presence of air. Acetate silk quickly loses its 
tensile strength at elevated temperatures, as do also wool and true 


© Where the regenerated rayons have been sized with gelatin or glue this — 


may give a nitrogenous odor on burning and cause it to be confused with 
true silk or wool.” 


Py) apelin Spee 


eee ay ee oe er 


> ie hr 


IDENTIFICATION OF RAYONS re) 


silk but to a less extent, and this may serve as a quick test to dis- 
tinguish it from the other rayons and cotton. One or two passes 
above a Bunsen flame is usually sufficient to disrupt acetate silk 
yarn or cloth. 


The Acetate Test 


The “acetate test’ has frequently been recommended as a test 
for acetate silk. Possibly the best method of making this test is to 
dissolve the fiber in a little chloroform and boil this solution with 
a normal solution of sodium hydroxide. Dilute with water, and 
filter off the precipitated cellulose and evaporate the solution just 
to dryness. Add sufficient water to dissolve the residue and acidify 
with sulfuric acid. Add a little ethyl alcohol and the same amount 
of concentrated sulfuric acid, warm, and if the sample contains 
acetate silk, the odor of ethyl acetate may be detected. 

Trotman and Trotman?® suggest boiling the rayon sample with 
a solution of potassium hydroxide, when potassium acetate is 
formed in the presence of acetate silk. This filtered solution may 
be concentrated, carefully neutralized, and a little neutral solution 
of ferric chloride added. If acetate silk was present, the red color 
of ferric acetate is apparent and upon boiling, a red precipitate of 
basic ferric acetate is formed, while acetic acid is liberated and its 
odor may be detected. 

As a shorter test, the filtered potassium hydroxide solution, 
after boiling the sample, may be concentrated to a small volume, 
cooled, and acidified with sulfuric acid. If the sample contained 
acetate silk, the characteristic odor of acetic acid is present on 
warming. 


The Acetamide Test 


Clayton? proposes the acetamide test, when other methods fail, 
for acetate silk. This may be used on either white or dyed fibers. 
A hard glass test tube is drawn out near the middle, so that the 
opening left can be subsequently closed quickly with a suitable 
flame. A few strands of the fiber are introduced into the tube and 
ammonia added to about one-tenth the capacity of the tube. Be- 
fore sealing the tube, the ammonia should be heated gently. to drive 
out most of the air, and if possible the fibers are arranged in the 
upper portion of the tube as sealed. The tube is then sealed, 


76 ACETATE: SILI 


surrounded by a safety screen, and the lower portion placed in a 
suitable oil bath, the temperature of which is slowly raised to about 
120 to 140° C., and held at this temperature for 30 to 60 minutes. 
On cooling the tube and opening it, the odor of a small amount of 
impure acetamide will be detected, if the fiber sample contained 
acetates. 


Distinguishing Lustron and Celanese 


Perhaps the most complete paper upon the identifiation of the 
rayons is that of Prof. Johnson.1 In addition to the acetic acid 
test just mentioned, he recommends the following reagents: 


1. Diphenylamine; a 1 per cent solution in concentrated chemi- 
cally pure sulfuric acid. 
2. Various dye solutions; 1 part of dyestuff in 1005 of water. 
a. Methylene Blue. 
b. Pontamine Scarlet B, or its equivalent. 
c. Sulfur Khaki Y, or its equivalent. 
3. Millon’s reagent: Dissolve metallic mercury in its own weight 
of chemically pure concentrated nitric acid and then dilute 
with an equal volume of water. 


Before making the colorimetric tests upon dyed rayon, it is 
usually necessary to “strip” the color from the fiber. This may be 
done by the usual methods with hypochlorite, peroxide, perman- 
ganate, hydrosulfite or a hydrosulfite-formaldehyde compound, 
such as Protolin AZ, in a solution containing acetic or formic acid. 
The latter method is recommended, but will not remove all dyes 
from acetate silk.1 Care must be observed that the stripping opera- 
tion does not so alter the rayon as to obviate the results of the iden- 
tification tests. Samples for testing should be of a white color, if 
possible, and free from ay oils, bleaching, or other chemicals 
or foreign matter. 


Dyeing Tests 


Lustron and Celanese may be distinguished by boiling a few 
threads of the sample in 10 or 15 cubic centimeters of the 2a 
Methylene Blue solution as above, acidified with 1 or 2 cubic centi- 


4 Also see Chapter XXXV. 


IDENTIFICATION OF RAYONS rer 


meters of acetic acid. Wash the dyed samples well in water. The 
Lustron retains a deep blue color, but the color of the Celanese 
washes out to a comparatively pale blue. This difference is entirely 
due to, and is typical of, the affinity of the two fibers for the basic 
dyes.° While the basic dyes have a greater affinity for Lustron 
than any other known textile fiber, this is decidedly not the case 
with,Celanese. Dort® states that this test is not always reliable. 

Ginsberg* states that if a rayon sample is placed in a solution of 
3 per cent Methylene Blue and 2 per cent acetic acid, nitro silk 
will rapidly assume a marine-blue color, quickly exhausting the 
bath, while viscose and cuprammonium silks are only slightly dyed 
and leave the remaining bath thick. Acetate silk (probably Cel- 
anese) is not dyed, but after soaking in diluted alcohol or other 
suitable swelling solvents, the dyestuff is quickly absorbed into 
the fiber. If Lustron and Celanese are dyed together in the. same 
dye bath at the same time with a basic dye such as Rhodamine or 
Malachite Green, the Lustron will take on a very full shade while 
the Celanese will show only a comparatively light shade. Celanese 
is claimed to have a slightly greater affinity for the Ionamines and 
S. R. A. dyes than Lustron and it has been stated that they may 
be differentiated by this test. None of the other rayons are dyed 
by either the Ionamines or dispersal dyes, however, some of them 
stain wool and true silk to some extent. The luster of Celanese 
and Rhodiaseta is impaired by boiling it in pure water, while Lus- 
tron withstands this treatment very well. 


True Silk 


Upon treating the unknown sample with Millon reagent and 
warming gently, true silk is colored a brick-red, while all of the 
rayons, ineluding acetate silks, are unstained. Animal fibers may 
also be identified by the fact that when boiled with a decolorized 
solution of magenta and afterwards well washed, they assume a 
pink color, while all other fibers are colorless. This reagent may be 
prepared by dissolving 0.1 gram of magenta (fuchsin) in 100 
cubic centimeters of water and adding sulfurous acid solution until 
it is just decolorized. The sulfurous acid solution is conveniently 


© This test should be used only in the proven absence of nitro silk. 


78 ACETATE SIC 


prepared by dissolving sodium bisulfite in water and acidifying 
with hydrochloric acid. 


Ammoniacal Nickel Oxide Solution 


Ammoniacal nickel oxide reagent swells but does not dissolve 
either acetate or the older rayons. However, it dissolves true silk 
almost immediately. It is prepared in almost the same manner as the 
corresponding copper oxide reagent. Dissolve 5 grams of nickel 
sulfate in 100 cubic centimeters of water and add sodium hydroxide 
solution until the nickel hydroxide is completely precipitated. 
Wash the precipitate free of alkali and dissolve in 25 cubic centi- 
meters each of concentrated ammonia and water. 


Alkaline Copper Solution 


Copper-glycerol reagent may also be used to distinguish between 
rayon and true silk. While it quickly dissolves the latter, it is with- 
out action on any of the rayons, including acetate silk. This reagent 
is prepared by dissolving 10 parts of copper sulfate in 100 cubic 
centimeters of water, adding 5 parts of glycerol and then suff- 
cient concentrated aqueous potassium hydroxide to completely dis- 
solve the precipitate at first formed. Of course, the acetate silks 
lose luster on warming in this reagent. 

According to Formhals® true silk, even if weighted and dyed, 
may be distinguished from rayon by treating a small portion of the 
sample for a short time in a few cubic centimeters of concentrated 
sulfuric acid, diluting the mixture with water, adding sodium hy- 
droxide to alkalinity, and then adding diazotized p-nitroaniline 
solution. Natural silk gives a red solution under these conditions, 
while the rayon solution is yellow. Very probably the presence 
of wool would also give a red solution, similar to silk. 


Nitro Silk 


Upon wetting a fiber of nitro silk with the diphenylamine solu- 
tion, it is at once colored blue and dissolves in a few minutes. 
Another method suggested for identifying the nitro silk is to dis- 
solve the samples in concentrated chemically pure sulfuric acid and 
add brucine sulfate to the solution. This gives a bright red color 


IDENTIFICATION OF RAYONS 79 


when nitro is present. Undenitrated nitro silk is soluble in amyl 
acetate and very flammable. 

Schwalbe® states that if 0.2 gram of rayon is heated in a test 
tube with 2 cubic centimeters of Fehling’s solution, nitro silk im- 
parts a green color to the solution, probably due to its oxycellulose 
content, while viscose and cuprammonium silks do not decolorize 
the solution under the same conditions. In some cases the nitro 
silk may have a yellowish to red copper oxide precipitate on the 
fiber. 


Distinguishing Viscose and Cuprammonium Silks 


If true silk, acetate and nitro silks are absent, viscose and cu- 
prammonium silks may be distinguished by comparative staining 
with the Pontamine Scarlet B (Johnson’s 20 solution) or Sulfur 
Khaki Y (2c), both of which have a greater affinity for the cu- 
prammonium than for viscose silk. In this test, as well as in all 
others, it is recommended to use standard samples of the rayons 
from known sources for comparison in running the tests. In dye- 
ing with the scarlet, about 1 per cent of dyestuff, on the weight of 
the fiber, should be used. With the Khaki, use about 3 per cent 
dissolved with 2 to 4 times as much fused sodium sulfide as dye- 
stuff. A 1 in 2000 solution of Naphthylamine Black 4B (Cassella, 
a mixture of C. I. Nos. 246 and 308) dyes cuprammonium™ 
dark bluish-gray and viscose a light reddish-gray, or a light bluish- 
gray (linters )from a hot neutral dye bath. It will be noticed un- 
der the ruthenium-red tests that, whereas viscose is colored a bright 
rose, cuprammonium remains almost colorless. 


The Silver Tests 


Gotze” states that a 1 per cent ammoniacal silver nitrate solution 
colors viscose a distinct brown, while under the same conditions 
cuprammonium silk remains colorless. He attributes the brown 
color to a deposit of finely divided silver in or on the fiber and not 
to silver sulfide. 

Rhodes® obtains better results with a reagent containing 1 per 
cent of silver nitrate, 4 per cent of sodium thiosulfate, and 4 per 


80 ACETATE SIDE 


cent of sodium hydroxide, than with Gotze’s reagent. The reagent 
is prepared by dissolving each chemical separately in water, adding 
the silver nitrate to the sodium thiosulfate solution, and when the 
precipitate which at first forms has dissolved, adding the sodium 
hydroxide solution. This is brought to a boil and filtered. The 
sample should be immersed for one minute in the boiling solution, 
when viscose is colored a deep red-brown, while cuprammonium 
silk remains almost white. The color of the viscose sample is very 
similar to a 2.5 to 4 per cent Chlorazol Brown M (C. I. No, 420, 
B. D. C.) dyeing. Nitro silk is also stained by both the Gotze and 
Rhodes tests, very probably due to its sulfur content, from the 
denitrating process, but may readily be differentiated from viscose 
by the diphenylamine test. Table XX gives the results obtained 
by these two tests. 


TABLE XX 


CoLors ON VISCOSE, CUPRAMMONIUM AND NITRO SILKS BY THE 
GotzE AND RHODES TESTS AS COMPARED WITH CHLORAZOL Brown M® 


Variety Gotze Test Color Rhodes Test Color 
Cuprammonium Silk 0.0% Chlorazol Brown M 0.0 % Chlorazol Brown M 
Viscose Silk 0.3% Chlorazol Brown M 2.5 %Chlorazol Brown M 
Vistra Silk 1.0% Chlorazol Brown M 4.0 %Chlorazol Brown M 
Nitro Silk 

(denitrated) 0.6% Chlorazol Brown M 3.25% Chlorazol Brown M 


Harrison® used a thiosulfate silver solution as a test for oxy- 
cellulose, consequently, certain forms of cuprammonium which are 
known to contain oxycellulose, may become colored by this test 
but the shade is grayer or less brown in character. Rhodes*® 
points out that this grayer color in the presence of oxycellulose 
indicates that the brown on viscose and denitrated nitro silks, both 


of which contain sulfur, is not due to a precipitation of colloidal. 


silver but to the presence of sulfur in the fiber. 

According to Kraise!? the very fine viscose silks now on the 
market do not always give exactly the same colors in certain 
tests as the heavier fibers. He gives Table No. XX-A showing 
the colors on the various fibers by the different methods and 
recommends the Rhodes and Naphthylamine Black tests. 


IDENTIFICATION OF RAYONS 81 


TABLE XX-A 
CoLor TEsts On Various RAYONS 


Variety Naphthylamine Black 4B17 Gotze7 Rhodes8 
Viscose, 7-8 den. Light reddish-gray Rust-brown Very dark blackish- 
rown 
Viscose, 4 den. , Light reddish-gray Rust-brown Lighter blackish-brown 
Viscose (linters) 7-8 den. Light bluish-gray Light rust-brown Still lighter blackish- 
brown 
Cuprammonium 1-2 Dark bluish-gray Light yellowish- Very light gray 
den. brown 
Nitro Light reddish-gray Rust-brown hoe dark blackish- 
rown 
Acetate Light reddish—gray Light brown Bluish-black 


The Sulfide Test 


Schreiber and Hamm?® recently found that the traces of sulfur 
compounds remaining in viscose silk cause it to give a sulfide test 
with lead acetate paper which is not given by cuprammonium 
silk. In making this test they recommend that a 5 gram rayon 
sample be placed in a flask with 100 cubic centimeters of water 
and 3 cubic centimeters of concentrated sulfuric acid. The mouth 
of the flask is closed with a diaphragm of filter paper saturated 
with a 10 per cent solution of lead acetate, and the flask heated 
over a moderately boiling steam bath for 4 hours. If at the end 
of this time the exposed part of the lead acetate paper is stained 
brown or black, the sample is viscose, while the absence of color 
indicates cuprammonium silk. They do not give any data upon 
the behavior of nitro or acetate silks under this test, but they 
were unable to obtain a positive test for carbon disulfide remaining 
in viscose. 

Sulfuric-Acid Test 


Maschner™ states that the rayons may be identified by placing 
0.2 gram samples in small dry Erlenmeyer flasks standing on a 
white surface. Add about 10 cubic centimeters of chemically pure 
concentrated sulfuric acid simultaneously to each flask and shake 
gently to thoroughly wet the fibers. Note the immediate effect 
and continue the observation for about an hour and a half. Nitro 
silk is at first quite colorless but in 40 to 60 minutes the liquid 
assumes a weak yellowish tone. Cuprammonium silk immediately 
takes on a yellow to yellowish-brown tone and the liquid becomes 
yellowish-brown after 40 to 60 minutes. Viscose silk is at once 
turned reddish-brown by the acid and after 40 to 60 minutes the 
liquid is a rusty-brown color. 


82 ACETATH Siig 


Clayton? reports that the concentrated sulfuric-acid test used to 
distinguish between viscose and cuprammonium rayons appears 
to be based partly on the assumption that the viscose gives hy- 
drolysis products of a deeper color than those of cuprammonium. 
He claims that these tests cannot be regarded as conclusive, and 
that in carrying out the test it is important to give particular atten- 
tion to any color change occurring in the first 15 to 30 seconds. 
The viscose becomes yellowish-brown, while the cuprammonium is 
colored a reddish-yellow. ‘Tests for copper in the latter fiber are 
not always successful either, and he recommends a dyeing test as a 
check upon the results obtained by the other methods. On account 
of the greater hydration of the cuprammonium rayon, it is invari- 
ably dyed more deeply than viscose rayon when they are simultane- 
ously placed in the same direct dye bath. He recommends Sun 
Yellow R in very dilute solution, in the presence of a little alkali, 
for this test. 

Ruthenium-Red Test 

Matthews! gives a very good account of the ruthenium-red test 
on various fibers. Ruthenium is one of the rare metals and most of 
its salts give an intensely red solution in water. This is especially 
true of the aqueous solution of the complex salt of ammonia with 
ruthenium oxychloride, Rug(OQH)2Cl4(NH3)7.3H2O. This re- 
agent has been recommended for use in the microscopic examina- 
tion of various fibers. While it is soluble in water, it is insoluble in 
both glycerol and alcohol. Ruthenium red is without action on 
fresh lignified tissue or that preserved in alcohol, but after the ac- 
tion of alkalies or sodium hypochlorite, the tissue is colored a 
bright rose. It colors the gums and pectin matters so widely 
found in vegetable fibers, as well as oxycellulose, but does not 
color pure cellulose, such as the clean normal cotton fiber. Raw 


unbleached cotton is quickly colored due to the presence of pectin 


or cuticle. Textile fibers containing pectocelluloses, such as linen, 
ramie, hemp and jute are strongly colored. Kapok is practically 
unstained, bleached wool is uncolored even after 12 hours and 
bleached true silk, which is at first not colored, becomes a rose 
color on standing. This reagent should be freshly prepared by 
dissolving 0.01 gram in 10 cubic centimeters of water. It is un- 
stable in strong light. 


IDENTIFICATION OF RAYONS 83 


Haerry™ reports that ruthenium red is useful as a reagent for 
the identification of the rayons. Upon treating the rayon sample 
with the above reagent and allowing it to stand 12 hours, viscose 
becomes a distinct pink, more pronounced on standing. Deni- 
trated Chardonnet (nitro) silk first becomes red but is more violet 
on standing. Cuprammonium silk is only slightly pink even after 
standing 12 hours; and acetate silk, which should remain uncol- 
ored, is sometimes irregularly tinted after 12 hours. This irregu- 
lar tinting of acetate silk indicates irregularity in its composition 
‘and the test may have some value in detecting this fault. Rayon 
which has received the sthenose treatment is not colored. 


The lIodine-Zince Chloride Test‘ 


According to Schwalbe® it is possible to distinguish between 
viscose and cuprammonium silks by treating them with iodine-zinc 
chloride reagent, and washing with water. Both silks are at first 
colored, but whereas the viscose holds the bluish-green color for 
some time, the brown color of the cuprammonium silk soon washes 
out. Acetate silk is colored a distinct yellow by this reagent, and 
nitro a reddish-violet. This reagent is prepared by dissolving 20 
grams of zinc chloride, 2 grams of potassium iodide, and 0.1 gram 
of iodine in 15 cubic centimeters of water. Maschner! reports 
that this test is not very satisfactory as different samples of viscose 
and cuprammonium silk react in different ways. Also see the 
zinc chloride-iodine test for mercerized cotton in Chapter VI. 


The Lodine-Sulfuric Acid Test? 


The United States Bureau of Standards recently recommended 
a sulfuric acid-iodine solution, for the identification of rayons. 
This reagent, possibly giving about the same result as Hoehnel’s 
iodine reagent, is freshly prepared for each test by dissolving 1 
gram of potassium iodide in 25 cubic centimeters of water and 
adding iodine crystals to saturation. Pour off the clear solution 
and dilute this to about 25 to 50 per cent of its strength with 
water. Add an equal volume of 95 per cent sulfuric acid. When 


‘ Where the fibers have been sized with a farinaceous product, any colori- 
metric identification test involving the use of iodine may give a misleading 
blue color.” 


84 ACETATE SILK 


treated with this solution, viscose silk turns a blue color, acetate 
yellow, nitro violet, and cuprammonium a light blue. Haller and 
Ruperti!® state that fully hydrolyzed Celanese gives a blue color 
with iodine in potassium iodide-sulfuric acid reagent, instead of 
the yellow obtained on ordinary Celanese. Gelatin silk, which is 
not a commercial product, is colored a yellowish-brown. 

Clayton? recommends iodine solution as a quick method of 
identifying the various rayons. Celanese turns yellow to yellow- 
‘sh-brown when immersed in this solution, and the color is fairly 
fast to washing in water. Viscose and cuprammonium silks are 
colored a deep bluish-black by the same treatment but become 
very pale blue on continued washing. This test may be applied to 
the dyed Celanese fibers, provided the coloring is not too deep. Un- 
fortunately wool and true silk are also colored yellow by iodine 
solutions but the burning test serves to distinguish these very 
readily by their nitrogenous odor. Another method of differen- 
tiating between true silk and wool on one hand and acetate silk — 
on the other is to immediately place the yellow-colored fibers, 
after rinsing off the iodine solution, in a cold 1 per cent solution of 
caustic soda. The color of the true silk or wooljs almost in- 
stantly discharged, while the color of the Celanese persists for some 
time, When using very fine filaments for this test, the strength of 
the caustic solution should be reduced. 

When Celanese is partially hydrolyzed (saponified) by treatment 
with a cold, very dilute solution of caustic soda, it absorbs iodine 
from the solution with greater avidity than does the normal fiber. 
Even though the hydrolysis may be sufficient to allow staining of 
the fiber by direct dyes, the color of the iodine-stained fiber is only 
a light yellowish-brown after washing, which indicates a rather 
incomplete hydrolysis. However, when the acetate silk is boiled 
for a half a minute in a 1 per cent solution of caustic soda, it 
reacts towards the iodine solution in the same manner as the other 
rayons and mercerized cotton. This test may therefore serve as a 
quick, rough test for partially or unevenly hydrolyzed acetate silk. 


Identification by Refractive Index 


The comparative low refractive index of acetate silk, which was 
mentioned as 1.474 to 1.479 in connection with its properties, 


IDENTIFICATION OF RAYONS 85 


offers a very easy and simple method of identifying the undyed 
fiber either alone or in combinations with other fibers, under the 
microscope. It is well known that when a comparatively trans- 
parent colorless material is submerged in a liquid of approxi- 
mately the same refractive index, it loses detail and under certain 
conditions is distinguishable only with difficulty. This principal 
may be used to identify, or rather to obliterate, the undyed acetate 
silk in a mixture of fibers. 

If undyed acetate silk fibers, or materials containing it, are 


.mounted on a microscopic slide in a medium of approximately 


the same refractive index as the fiber, the acetate fibers become 
practically invisible under the microscope. In fact in many in- 
stances there is enough visible change in the appearance of the 
fabric for an experienced worker to identify the acetate without 


putting it under the microscope. Through the microscope, only 


the fibers other than acetate are visible. When the fiber is dyed in 
light shades, this method is sometimes useful, but with heavy 
shades the color is so plainly apparent that the method is not often 
of value. 

The refractive index of glycerol is 1.471 and that of lemon oil 
1.473 to 1.476 at 25° C. W. Massot was possibly the first to 
suggest the use of glycerol in this manner, while Worden" sug- 
gested lemon oil for the same purpose. With Lustron and Cel- 
anese of the present type, lemon oil works very satisfactorily, while 
glycerol is a good substitute but is not quite so effective. The 
method is easy, quick and almost startling in its results to those 
who are not familiar with this phenomenon. In the above mediums, 
all other commercial fibers stand out clearly and distinctly, only 
the acetate silk disappearing. 

Herzog? states that true silk may be identified and obliterated 
by a similar method. If a fiber of true silk is mounted in aniline, 
refractive index 1.599, and examined under a microscope with a 
Nicol prism, it is almost invisible when its longitudinal axis is at 
right angles to the plane of polarisation of the prism. It becomes 
more and more visible, when the stage is rotated, until it reaches 
a maximum of visibility at right angles to the original position. 
The older rayons have a refractive index between that of true silk 


86 ACETATE. Sit 


and acetate silk, and are therefore distinctly visible at all positions 
of the stage and prism. 

Garner!8 suggests that acetate silk may readily be distinguished 
from the other rayons by the differences in their specific gravi- 
ties and mentions an aqueous 40 per cent solution of potassium 
iodide, sp. gr. 1.4, as suitable for this purpose. In this solution, 
acetate silk, specific gravity about 1.3, floats, while viscose and cot- 
ton, specific gravity about 1.5, sink. 

Another simple test for either white or dyed acetate silk is by 
means of the electroscope, and is based upon the fact that all vege- 
table fibers and rayons, with the exception of acetate silk, will 
remove the static charge from the electroscope, while acetate silk, 
true silk and wool do not dispel the. static charge. 


A. S: Tc Moe 


Sub-Committee XV, of Committee D-13 of the American So- 
ciety for Testing Materials, in a recent revised report of proposed 
rayon specifications have proposed the following as tests for the 
different rayon varieties: 

Acetate: Twist fibers to tight wad and cautiously approach to 

match flame. 

a. Acetate silks “melt” or “fuse” and burn more slowly than 
other rayons and harden at once into a light brittle substance, 
globular in appearance. 

b. Viscose, nitro and cuprammonium silks all burn like 
cotton; that is, with no odor and leaving very little ash. 
Acetate silk is readily soluble in pure acetone to concen- 
trations of not over 1 per cent. This serves as a confirma- 
tory means of differentiating acetate silks from other ray- 
ons, which are not soluble in acetone.® 


Nitro: Moisten the thread with a solution consisting of 1 per 


cent diphenylamine in concentrated sulfuric acid. 
a. Nitro silks assume immediately a deep blue color. The 
fiber dissolves rapidly to a blue solution. 


b. Viscose and cuprammonium silk are not colored blue and 


dissolve more slowly. 


® See footnote, page 71. 


= <at 7. 


i iti 


IDENTIFICATION OF RAYONS 87 


Cuprammonium: Immerse the thread for a minute in a boiling 
solution consisting of 1 per cent silver nitrate, 4 per cent 
sodium thiosulfate, and 4 per cent sodium hydroxide.® 
a. Cuprammonium silk will remain unstained. 

b. Viscose silk will be stained a brown or reddish-brown 
color. This reaction will also produce a brown stain on 
nitro silk. 


4 


"In preparing this reagent, dissolve the silver nitrate and sodium thiosul- 
fate separately. Add the first to the second and the cloudiness will dis- 
appear. Add the previously dissolved sodium hydroxide. Make up to 
correct volume, bring to boil, and filter. 


References 


*A. K. Johnson, American Dyestuff Reporter 14, 105-7 (1925). 

*E. Clayton, Silk J. 2, 45-7 (1925). 

*R. G. Dort, American Dyestuff Reporter 15, 265 (1926). 

*I. Ginsberg, American Dyestuff Reporter 12, 652 (1923). 

®°R. Formhals, Chem.-Zeit. 43, 386 (1919). 

°C. G. Schwalbe, Farb. Zeit. 18, 273 (1907) and Ber. 4o 1347-51 (1907). 

"K. Gotze, Textiber. 6, 769-70 (1925). 

®O. S .Rhodes, J. Textile Inst. 17, 75-6 (1926). 

°W. Harrison, J. Soc., Dyers and Colourists 28, 361 (1912). 

7?P. Maschner, Farb. Zeit. 21, 352-3 (1910). 

1 J. M. Matthews, “Textile Fibers.” 

J. A. Haerry, “Artificial Silks.” 

%R. Haller and Ruperti, Leipzig Monats. 40, 399 (1925). 
ae C. Worden, “Technology of Cellulose Esters,” 1916, Vol. VIII, p. 

® A. Herzog, Kunststoff 7, 277-8 (1917). 

6S. R. Trotman and E. R. Trotman, “Bleaching, Dyeing and Chemical 
Technology of Textile Fibers.” (1925) p. 64. 

™P. Krais, Papier-Fabr. 24, 330-1 (1926). 

#8 W. Garner, J. Soc. Dyers and Colourists 42, 269-72 (1926). 

*“Dyeing and Printing of Artificial Silks,’ British Dyestuffs Corpora- 
tion (1926). 

*°W. T. Schreiber and H. A. Hamm, Testile World 70, 2029 (1926). 

Poukd. (iN. y.) 15, No. 9, 35 (1925). 

* Wm. Bennett, Silk J. 3, No. 31, 59, 61 (1926). 


In a Special Bulletin describing their ‘““Method To Distinguish Viscose 
From Cuprammonium Rayon,” Schrieber and Hamm give the following 
additional bibliography of rayon identification: 

Dobroyd, J., Distinguishing between artificial silks; Posselt’s Textile 
J. 10, No. 4, 107-9 (1909); J. Textile Inst. 3, 210 (1912). 

Anon., Examination of artificial silk; Posselt’s Textile J. 2. No. 4, 107-8 
(1909); J. Textile Inst. 3, 656 (1912). 

cies, L. J., The identification of artificial silks; Am. Silk J. 32, No. 12, 
49-51. 

Beltzer, F. J. G., Differentiation of natural and artificial silks by means 
of ruthenium red; Mon. Sci. 55, 633-41 (1911) ; Chem. Abs. 6, 297 (1912) ; 


88 ACETATE SILK 


jf aa Chem. Ind. 30, 1206 (1911); J. Soc. Dyers Colourists 28, 301-3 

(1912). 

Matos, L. J., The recognition and separation of varieties of artificial 
silk; Leipzieger Farber Z. 63, 53-6; Chem. Abs. 8, 2810 (1914). 

Anon., Identification of artificial silks; Bull. Soc. d’Encouragement 
PInd. Nat. 61, No. 1601, 507 (1919); J. Textile Inst, 11, 24 (1920). 

Krais, Distinction between cuprammonium and viscose silk; Textile 
Forschung 2, 64-5 (1920); J. Textile Inst. 11, 266 (1920). 

Springer J. F., Determining varieties of artificial silk; Am. Silk J. 42, 
No. 7, 81 (1923). 

Lang, Konrad, The identification of cuprammonium artificial silk; 
Textilber, 4, 231 (1923); Chem. Abs. 17, 2366 (1923). 

Anon., Chemical reactions of the different kinds of artificial silks; 
Avenir Textile, (Feb. 1922); Industrie Chim. 9, 503 (1922) ; Chem. Abs. 
77,639 (1923). 

Ristenpart, C., and Petzold, K., The identification of cuprammonium 
silk: Textilber. 5, 179-80 (1924) ; Chem. Abs. 18. 1754 (1924). 

Humphries, R., Laboratory methods for distinguishing silk and imita- 
tions: Suk J. 1, No. 2, 20 (1924). 

ODD Distinguishing different kinds of rayon; Textile World 68, 1798 
Anon., Tests for identifying artificial silks; Am. Dyestuffs Reporter 14, 
Rasser, E. C., Die kunstide ihre unterscheidung, unlersuchung und 

prufung; Kunstseide 7, 117-20 (1925). 

Anon., Qualitative tests for rayons; Textile World 70, 763 (1926). 

404 (1925). 


89 


IDENTIFICATION OF RAYONS 


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POAPTER VI 


THE DETECTION OF COTTON WHICH HAS RECEIVED 
THE MERCERIZATION TREATMENT AND ESTIMA- 
TION OF THE EXTENT OF THIS TREATMENT 


WHILE mercerized cotton and other vegetable fibers do not 
_belong in the rayon classification, their frequent presence in ace- 
tate silk combinations and the difference in their dyeing properties, 
as compared with both unmercerized cotton and the rayons, is 
sufficient justification for including the methods of detecting fibers 
which have received the mercerizing treatment. Practically all 
dyers are familiar with these differences in dyeing properties? but 
most of them are not so familiar with the methods of detecting 
and estimating the extent of this treatment. 

Microscopic examination of the fiber or fabric has been and still 
is widely used as a method of detecting mercerized cotton, but the 
many widely different finishing treatments now given to all classes 
of fabrics, renders the microscopic method of detecting mercerized 
cotton more and more difficult and unreliable. Of course the 
differentiation of mercerized cotton and rayon under the micro- 
scope is very quick and accurate. 


The Iodine Test 


One of the first successful chemical tests for the identification 
of mercerized fiber is that of Hubner? who gives a very complete 
and detailed account of his experiments. Hubner found that if 
cotton hanks which have been mercerized with sodium hydroxide 
solution of different strengths are immersed in a 0.01 normal 
iodine solution along with untreated cotton, at the moment of 
immersion a beautiful graduation of color is obtained, increasing 
in depth with the increase in strength of the soda solution used in 
mercerizing. After immersion for 5 minutes there is little differ- 
ence in the depth of coloration between the unmercerized and that 
mercerized with 10° Tw. (1.05 sp. gr.) sodium hydroxide solu- 


v1 


92 ACETATE SILK 


tion, while the hank treated with 20° Tw. (1.10 sp. gr.) solution 
is more colored than the 10° Tw.; the 22° Tw., stronger than the 
20° Tw.; the 24° Tw., stronger than the 22°; the 26° Tw., much 
stronger than the 24°; the 28° and 30° Tw. each successively 
stronger than that proceding; the 40° Tw., much stronger than 
the 30° Tw.; the 45° Tw., stronger than the 40° ; the 50° Tw., 
much stronger than the 45°, while the 60 and 70° Tw. (1.3 and 
1.35 sp. gr. ) mercerized hanks are, if anything, rather lighter than 
the 50 Tw. (1.25 sp. gr.). Unmercerized hanks which have been 
steeped in this 0.01 normal iodine solution for 4 hours, after ex- 
posure to the air soon become white, while the mercerized samples 
show a color graduation depending upon the strength of the so- 
dium hydroxide solution used, as mentioned above. 

When the samples are immersed in 0.1 normal iodine solution 
and carefully washed in water, the typical brown coloration of 
both mercerized and ordinary cotton turns to a more chocolate 
shade. At a certain stage the ordinary cotton becomes rapidly 
decolorized, while the mercerized cotton turns a navy blue color, 
which, however, on repeated washings fades rapidly to white. 
With increased concentration of the iodine solution this blue color- 
ation becomes more stable, and Hubner recommends a solution © 
containing 20 grams of iodine in 100 cubic centimeters of a sat- 
urated aqueous solution of potassium iodide. The samples should 
be placed in this solution for a few seconds, when, after washing, 
ordinary cotton becomes a very light chocolate color, while the 
mercerized sample remains black. After further washings the 
untreated cotton becomes white, but the mercerized cotton re- 
mains a bluish-black color and fades only on prolonged washing. 

Hubner also reports that mercerized cotton assumes a very dark 
reddish-navy-blue shade, while ordinary cotton is only very faintly 
tinged reddish by treatment with zinc-chloride-iodine reagent. He 
obtained the best results with the following reagent: Prepare a 
solution (4) containing 280 grams of zinc chloride in 300 cubic 
centimeters of water, and a second solution (B) containing 1 gram 
of iodine, 20 grams of potassium iodide and 100 cubic centimeters 
of water. To 20 cubic centimeters of A, add 4 drops of B, which 
corresponds to about 0.00195 gram of iodine. If the samples are 


DETECTION OF COTTON 93 


allowed to remain in the solution for 24 hours, the unmercerized 
cellulose is colorless while the mercerized cotton is a bluish-violet 
color. During this long exposure the iodine slowly disappears 
from the solution. 

Kinkead* reports that the iodine test may be applied to flax 
yarns but that difficulty is encountered in applying it to linen cloths 
on account of the necessity for the complete removal of all traces 
of starch. A very slight trace of starch will give a deep blue 
color which entirely masks the reaction. 


- The Benzopurpurin Test 


The late Prof. Knecht* pointed out the remarkable difference in 
the behavior of ordinary and mercerized cotton dyed with Benzo- 
purpurin 4B on treatment with hydrochloric acid. Ordinary 
cotton dyed in this manner is at once turned blue by the hydro- 
chloric acid but mercerized cotton assumes a reddish-violet color, 
provided not too much acid is used. 

If the acid solution containing the dyed cotton sample is heated, 
and a dilute solution of titanous chloride slowly added, the color of 
both samples gradually diminishes in intensity, until, just before 
the complete decolorization, the ordinary cotton appears indigo- 
blue and the mercerized cotton red. This distinction is only visible 
in case the mercerized sample has been treated with caustic soda 
solution of over 30° Tw. (1.150 sp. gr.) strength, unstretched, or 
35° Tw. (1.175 sp. gr.) under tension. Further experiments by 
Knecht indicate that the amount of dyestuff (Benzopupurin 4B) 
taken up by cotton upon treatment for an hour in a 20 to 1 dye 
bath containing 3 per cent of dyestuff, 5 per cent of sodium car- 
bonate and 10 per cent of salt, varies gradually from ordinary 
cotton with increasing strength of the caustic solution, up to 70° 
Tw. (1.350 sp. gr.) caustic solution. 

Knaggs® proposes a simpler modification of Knecht’s Benzo- 
purpurin-titanous chloride test, and states that if samples of ordi- 
nary and mercerized cotton are dyed with a trace of the dyestuff, 
with or without a little salt, on dropping acid into the boiling dye 
bath until the ordinary cotton has become blue-black, the mer- 
cerized cotton will appear red. He proposes to make this. test by 
using a dye bath containing 5 cubic centimeters of a solution con- 


94 ACETATE SILK 


taining 0.1 gram of Benzopurpurin 4B, in 100 cubic centimeters 
of water, with or without a little salt, and dropping in about 2 
cubic centimeters of strong (34.5° Tw.) hydrochloric acid. He 
also states that while Congo Red GR gives the same test, Congo 
Red 4R is not very sensitive to acid, and discusses the theory as 
advanced by Knecht. 

Kinkead® points out the difficulties encountered in applying the 
Benzopurpurin test and says that it “does not command confidence 
in general, because different materials require different quantities 
of acid to render the distinction evident. It appears impossible 
to find an acid solution of such strength that it could be used as a 
general reagent. For instance, an acid solution which gives the 
reaction with a heavy closely woven damask in a satisfactory 
tanner, is much too strong when testing an open woven cloth or 
a small cutting of yarn. Such a strong solution, with these open 
weave materials, would turn both the mercerized and unmercerized 
samples a blue color, while if the acid solution is only sufficiently 
strong to turn the color of the open-weave unmercerized cloth red, 
then both samples of the heavy damask remain entirely unchanged 
when treated with this solution. Moreover, the depth of shade 
produced on the material by the Benzopurpurin is also a con- 
trolling factor, the deeper the color of the cloth, the stronger is 
the acid solution required to give the reaction. This method there- 
fore cannot be considered satisfactory, as in the absence of a 
similar piece of material known to be unmercerized, it does not 
give a definite indication.” 


The Kinkead Test 


Kinkead® gives one of the latest and probably most reliable 
methods of determining whether vegetable fibers, including cotton, 
linen, ramie and hemp, have received treatment with strong sodium 
hydroxide solution, as in mercerizing. A small sample of the 
desired material is stained by soaking it for a few minutes in a 
0.001 per cent aqueous solution of Methylene Blue (preferably 
zinc-free hydrochloride), containing 0.5 per cent of sodium car- 
bonate. The stained material is rinsed with distilled water and in 
the case of cotton, ramie or hemp, covered in a test tube with about 


rae io eel he ae ee ee 


eee LLON OF COTTON 95 


10 cubic centimeters of a 1 per cent sodium carbonate solution. 
In testing linen a 3 per cent carbonate solution is used in place of 
1 per cent. Four drops of iodine solution are then added. This 
iodine solution is prepared by dissolving 1 gram of iodine in 100 
cubic centimeters of 20 per cent aqueous potassium idodide solu- 
tion. The test solution is rapidly heated to the boiling point, 
poured off, and immediately replaced by fresh cold sodium car- 
bonate solution of the same strength as above; i.e., 1 per cent for 
cotton or 3 per cent for linen. Under this treatment the coloration 
- of the mercerized material becomes reddish-purple, that of un- 
mercerized material remaining blue, often with a greenish shade. 
If an unmistakable purple color is not obtained, it may be con- 
cluded that the material has not been mercerized by a normal 
process. 

In making the test, prolonged heating of the stained goods in 
the carbonate solution should be avoided as this removes consider- 
able color from the sample. In many cases, it will be seen that 
the color change occurs on very slight warming, and when a qualli- 
tative test only is required, this may be taken as sufficient evidence 
of mercerization. It is desirable to pour off the first carbonate 
solution as it contains some color due to stripping, which may tend 
to mask the color change. It also quickly cools the test piece, which 
is desirable. When the hot solution is allowed to act for about 
a minute, it may cause a slight color change, towards the purple, 
on unmercerized goods, but the addition of a cold soda solution 
restores the original blue color. In the same manner, a lightly 
mercerized sample may assume quite a reddish-purple color when 
hot, but becomes much bluer as the solution cools. 

The second solution should never be heated as almost any 
alkaline solution, however weak, will produce the color change on 
unmercerized material if allowed to act for sufficient time at a 
high temperature. The shade of the unmercerized material is 
quite unaltered by the carbonate solution under the conditions of 
the test. Even after remaining in the cold carbonate solution for 
3 or 4 hours, the shade of the unmercerized material will be only 
slightly changed. The difference between the colors of mercer- 
ized and unmercerized material is quite distinct after remaining 


96 ACETATE SILK . 


in the carbonate solution for 3 days. Table XXII gives the 
colors obtained on materials mercerized under various conditions. 
An important factor in this test is that acid treatment or bleach- 
ing after mercerizing, even if drastic, does not appear to affect 
the result of the tests. 


TABLE XXII 
CoLor oF MERCERIZED CELLULOSE WITH KINKEAD TEST® 


nT 


Strength of NaOH 
Lia, 


Sp. Gr. Color Change 
OE eee 
0.0 1.000 Bright blue, no change. 
20. 1.100 Only very slightly redder. 
30. 1.150 Definitely redder. . 


40.and 50.1.200 to 1.250 Full purple and definitely the reddest of the series. 
60.and 70.1.300 to 1.350 Rather bluer than 40° and 50°. 


Sulfuric Acid-Formaldehyde Test 


Mennell® states that mercerized cotton is more readily attacked 
by sulfuric acid than normal cotton, and that while 1.375 sp. gr. 
sulfuric acid has practically no action on normal cotton, mercerized 
cotton is appreciably affected. The action of 1.600 sp. gr. sulfuric 
acid diluted to 1.375 with 40 per cent formaldehyde solution, is 
even greater than that of the sulfuric acid of this strength alone. 
This latter reagent may be prepared by diluting 320 cubic centi- 
meters of 1.600 sp. gr. sulfuric acid with 260 cubic centimeters of 
40 per cent formaldehyde solution. The mixture is about 1.375 
sp. gr. The sample to be tested, together with standard samples 
of both normal and mercerized cotton, is treated in this reagent for 
2 minutes at room temperature. They are then well washed and 
neutralized with hot dilute sodium carbonate solution. 

The effect of the sulfuric acid-formaldehyde reagent on the 
samples is very clearly shown on dyeing them with most sub- 
stantive dyes, but Chlorazol Sky Blue GW is suggested as particu- 
larly suitable for this purpose. The samples should all be dyed 
together in a slightly alkaline (with sodium carbonate) very dilute 
boiling dye bath. The amount of dyestuff to be used may be deter- 
mined by experiment but usually by using a dye bath which gives 
a 0.1 per cent shade, on the weight of the cotton, on the normal or 


eae eat ae 


cc Se 9 age gst pal a tar 


DETECTION OF COTTON a 


unmercerized sample, a well mercerized sample will be colored — 
equivalent to about a 0.8 per cent dyeing. 

Before testing dyed samples, the color should be stripped with 
sodium hypochlorite or hot alkaline hydrosulfite. The stripping 
operation does not affect the test in any way. The acid-formalde- 
hyde reagent keeps well and the formation of a para-formaldehyde 
sediment does not interfere if it is mixed well before using. The 
colors obtained are permanent, which is an advantage over the 
Hubner test and by comparing the colors obtained on the various 
samples, it is possible to estimate the degree of mercerization. 


Haller’s Method 


Haller? estimates the degree of mercerization of cotton samples 
by dyeing them together with standard mercerized samples and 
then comparing the amounts of white, black, and pure color tone 
in the dyed samples in the Ostwald chromometer. He states that 
while the method is rapid it is somewhat less accurate than the 
titanous chloride method of Knecht. Examination of the color 
contents of cotton fabrics with sodium hydroxide of 2 to 30° Be. 
(1.014 to 1.261 sp. gr.) and afterwards dyed with Diamine Blue 
3R, Benzo Azurine, and Congo Red, shows that the black and 
white constants of the resulting shades remain constant from 2 to 
12° Be. (1.014 to 1.091 sp. gr.), then distinctly increase and de- 
crease respectively from 12 to 26° Be. (1.091 to 1.221 sp. gr.), 
and then remain constant. Simultaneously the content of pure 
color decreases similarly but less regularly. It is concluded that the 
chief mercerization effects are produced by sodium hydroxide of 
12 to 26° Be., although Knecht found that the mercerizing action 
distinctly starts with a 7° Be. (1.052 sp. gr.) solution. 


References 


1 Schaposchinkoff and Minajeff, Ae Farben und Textile-Chem., (1903) 
No. 13; (1904) p. 163; (1905) p. 

ak Hubner, Dees 0c. Chem. Ind. Sr 105-12 (1908). 

R. W. Kinkead, J. Textile Inst. 17, 213-9 T (1926). 

Ve Knecht, J. Soc. Dyers and Colourists 24, 67-74 (1908). 

gD: Knages, J. Soc. Dyers and Colourists 24, 112-3 (1908). 

®H. Mennell, J. Textile Inst. 17, 247 T (1926). 

7R. Haller, Textilber 7, 65-6 (1926). 


CHAPTER VII 
DYEING THE OLDER RAYONS 
Nitro, Viscose and Cuprammonium Suk 


Now that we have a better understanding of the constitution 
and properties of acetate silk and the points wherein it differs 
from the older rayons, it may be well to briefly review the methods 
of dyeing the older rayons; i.e., nitro, viscose and cuprammonium, 
so as to bring out even more clearly the differences in the dyeing 
properties of acetate silk and those of all other cellulose fibers. 
As the dyeing of these older rayons is so well understood by 
everyone in the industry, it is useless to go into detail here. 

In general the behavior of the older rayons to dyestuffs is simi- 
lar to that of cotton,! with this difference, that the older rayons, 
consisting of hydrocellulose, have a greater affinity for most dyes 
than has cotton cellulose. It naturally follows that in these cases 
for equal weights of the two substances, the rayon requires less 
dyestuff than the cotton. All varieties of rayon have an affinity 
for the basic dyes but some varieties have far more afhnity for 
them than others, and as usual, the affinity of the different mem- 
bers of the basic class of dyes for each type of rayon varies some- 
what from that of the other members of the same classification. 

As has previously been mentioned, Lustron acetate silk has a 
greater affinity for the strongly basic dyes than any other textile 
fiber. The affinity of Celanese acetate silk for certain basic dyes 
follows that of Lustron.2 The affinity of nitro, viscose and cu- 
prammonium silks for the basic dyes decreases in the order 
named. While acetate silk has no affinity for most of the direct 
cotton and sulfur dyes, these may be used on all of the older 
rayons. Certain vat dyes, under some conditions, have an affinity 
for acetate silk, but practically all of them are used upon the older 
rayons for very fast shades. 


98 


RR a an 


en eT ae 


Wiited-o. these — ee ee ee ee ee 


—— a eee 


PY GiiNG THE OLDER RAYONS 99 


Dyeing Nitro Rayon 


Nitro silk is also known as Chardonnet, nitrocellulose, collodion, 
pyroxylin, du Vivier, Frankfurter, soie de France, Meteor, Streh- 
lenert, Besancon, Hungarian, Tubize, and Lehner artificial silk. 
Nitro silk, as the variety of names indicate, is manufactured in 
many different plants and while all are similar in appearance, in 
most instances the product of each plant differs in some slight 
degree from that of the other plants. Nitro silk is usually more 
lustrous than natural silk, harsher and without the characteristic 
feel of true silk. It has been stated that the original undenitrated 
Chardonnet silk more closely approaches the present acetate silks 
in many of their desirable properties, than any other type of rayon. 

Nitro silk has a great affinity for the basic dyes, whereas viscose 
and cuprammonium are best dyed by substantive dyes. Nitro silk 
is dyed even to deep shades by the basic dyes without mordanting, 
probably due to its combined oxycellulose and hydrocellulose con- 
tent, but viscose and cuprammonium silks should first be mor- 
danted with tannin and tartar emetic before applying the basic 
dyes. The fastness of the basic dyes on nitro silk to washing is 
increased by top-mordanting them with tannin and antimony in 
the usual manner. On account of the high affinity of nitro silk 
for the strongly basic dyes, acetic acid is frequently used as a 
retard and to aid leveling in applying them to this fiber. The 
weakly basic dyes show much less affinity for nitro and therefore 
must be applied in short baths of high concentrations, or on a 
mordant, to give deep shades. 

In general, nitro silk has less affinity for the direct cotton dyes, 
as a class, than either viscose or cuprammonium. In fact, it has 
been stated that the affinity of the direct cotton dyes for all of the 
rayons, acetate included, is just the reverse of the affinity of the 
basic dyes as given above. However, the direct dyes are fre- 
quently used on nitro silk, especially for light and medium shades. 
The vat and sulfur dyes may also be used on nitro silk but in 
applying the sulfur dyes, care must be taken to avoid loss of luster 
and strength. 


100 ACETATE SILK 


Dyeing Viscose Silk 

Viscose silk is also known as vistra, staple fiber, xanthate, 
Luna, Stettiner, Du Pont and Celta* silk, and is prepared from 
solutions of mercerized cellulose in caustic soda and carbon disul- 
fide. It is a regenerated cellulose with a fine glossy appear- 
ance. Its affinity for dyestuffs is similar to that of mercerized 
cotton and it appears to have an intermediary affinity, for both the 
basic and direct cotton dyes, between nitro and cuprammonium 
silks. In other words, it has more affinity than nitro silk for the 
weakly basic dyes, but less affinity than the cuprammonium. 
Basic dyes may be used for pale and medium shades without a 
mordant, but for heavy shades it should be mordanted and dyed 
in the presence of acetic acid. | 

Wilson and Imison? found that the affinity of viscose silk for the 
direct cotton dyes varies not only with the method of manufactur- 
ing the rayon, but also with the molecular complexity of the dye- 
stuff used. They point out that in a general way, the inequality of 
different lots of viscose is less evident in applying direct cotton 
dyes of low molecular weight, than with those of higher molecular 
weight. They give a list of dyes showing their comparative level- 
ing powers. Further, dyeing at high temperatures is more likely 
to yield level shades than similar dyeing at lower temperatures. 

Hall‘ points out that in order to obtain the best results with 
the direct dyes on viscose the following points should be con- 
sidered: 


1. The higher the temperature of the dye bath, the more level 
the shade. 

2. In using direct dyes which have an affinity for viscose, the 
best results are obtained by the use of only soap in the dye 
bath. 

3 The use of sodium sulfate or chloride in the direct dye bath 
on viscose tends to produce uneven shades and their use 
should be reduced to the minimum. 


“Celta is a Swiss macaroni or hollow, soft, rough surfaced rayon with less 
than the usual luster. Sniafil artificial wool is a variety of viscose which 
has received a special finishing treatment. Most of the so-called “artificial 
wools” are also prepared from viscose. 


DYEING THE OLDER RAYONS 101 


4, In dyeing compound shades, dyestuffs having approximately 
the same leveling powers should be used as far as possible, 
as it is unwise to mix even dyeing products with those known 
to dye unevenly. 


On viscose the sulfur dyes frequently give uneven results and 
their use should for this reason be avoided unless the fastness 
requirements demand their use. Of course, this unevenness is 
not so noticeable in heavy shades as on the tints, and, therefore, 
in applying the Sulfur Blacks this trouble is less prevalent. While 
vat dyes are coming into more extensive use on viscose, most of 
it is at present dyed direct. As is the case with all other dyes, 
certain vat dyes are far more level dyeing* on the older rayons 
than are other members of the same class. 


Dyeing Cuprammonum Silk 


Cuprammonium silk, known also as glanzstoff, cupra, cuprate, 
cellulose cuprate, copper ammonium, copper, Despaisis, Eagle, 
Julich, Givet, Crinol, Elberfeld, Aachen, Langhaus, Fremery, 
Oberbrucher, Sirius, Aix la Chapella, Bemberg, Thiele, Pauly, 
and Parisian silk, is made by the ammonium copper oxide process 
and the different products are all similar in appearance and prop- 
erties. It has a very high luster, in some cases surpassing that of 
nitro silk, and its feel approaches that of true silk. Cupram- 
monium silk has less affinity for the basic dyes than either nitro or 
viscose silk, and for full shades the cuprammonium silk should 
be tannin mordanted. It has the highest affinity of any of the 
rayons for the direct cotton dyes, which give excellent results on 
this fiber. Sulfur and vat dyes are also used but care must be 
taken to avoid loss of luster. This rayon has a higher affinity for 
the weakly basic dyes than for those of strongly basic character- 
istics, which is exactly the reverse of the case with nitro silk. 
In applying the weakly basic dyes to tannin mordanted cupram- 
monium silk, 5 to 10 per cent of acetic acid may be used in the 
dye bath, adding the dye to the bath gradually and raising the tem- 
perature slowly to avoid unevenness, to as high as 70° C. (156° F.) 


102 ACETATE Sin 


General Dyeing Formulas for Rayons Other Than Acetate 


While it has been suggested to apply the direct dyes to viscose 
and cuprammonium at a temperature as low as 40° C. (104° F.), 
without doubt better penetration and more level results are ob- 
tained at higher temperatures. For instance, The Ciba Company 
recommend that their Chlorantine Fast dyes be applied to viscose 
from a 20 or 30 tol neutral salt bath containing 10 to 20 grams 
of sodium sulfate per liter of dye bath, entering the goods at 
32° C. (90° F.) and completing the dyeing within an hour at 60 
to 80° C. (140 to 175° F.). In dyeing light shades, and as an aid 
in leveling and penetrating, soap or Monopole oil and/or sodium 
borate, phosphate, or carbonate may be added to the dye bath. 

Some acid dyes are also used but they are not usually fast to 
washing and the basic dyes have such a high affinity for some 
varieties of the fiber that in some instances it is almost impossible 
to secure level shades. The basic dyes are usually applied at 
temperatures up to 40° C. (105° F.) to the previously wet-out 
rayon with 2 to 10 per cent of acetic acid. For heavy shades and 
colors of better fastness to washing with the basic dyes, a tannin 
and tartar emetic mordant should be applied in the same manner as 
on cotton. 

Mordanting Rayon 

In mordanting either viscose or cuprammonium silks for the 
basic dyes, the rayon should remain for 2 or 3 hours in a bath 
containing 2 to 5 per cent of tannin and 1 per cent of hydrochloric 
acid, on the weight of the goods, at 50° C. (122° F.). The ma- 
terial is then removed, the excess of liquor removed (but not 
rinsed), and treated for about 20 minutes in a fresh cold bath con- 
taining 1 to 2.5 per cent, or about half of the percentage of tannin 
used, of tartar emetic. Hall* states that more even shades are 
obtained on viscose mordanted with Katanol than on tannin- 
antimony mordanted viscose, and gives a table to support this 
statement. If particularly fast dyeings are wanted, such as for 
cross-dyeing, the basic dyes should also have a top mordant by 
repeating the above process after dyeing. Basic dyes are often 
used to top the substantive dyes on rayons, thus brightening the 
shade. 


2 


Peet THE, OLDER RAYONS 103 


When the sulfur dyes are used on the rayons they are usually 
applied from a 25 to 1 dye bath containing the same quantity of 
sodium sulfide as dyestuff, 1 to 4 per cent of sodium carbonate 
and 5 to 25 per cent of sodium sulfate, dyeing at 38 to 49° C. 
(100 to 120°F.) for about an hour. Copper vessels must not be 
used. The vat dyes are now coming into more general use on the 
older rayons and are applied in the usual alkaline hydrosulfite 
vat. In general they have less affinity for nitro than for the viscose 
and cuprammonium silk. 

Really good deep blacks on rayon, such as on hoisery, are usually 
obtained by first applying dyes of the Diazo Black type, diazotiz- 
ing with sodium nitrate and hydrochloric acid, and then developing 
with B-naphthol or phenylenediamine, in the same manner as in 
dyeing cotton. Brown shades of good fastness to washing and 
cross dyeing may be obtained with Primuline and a Diazo Black, 
diazotized and developed with resorcinol or phenylenediamine. 
Brown shades of good fastness to light may be obtained with sul- 
fur dyes. 

The fact that acetate silk cannot be dyed fast shades by any of 
the foregoing methods greatly hindered its use in the textile indus- 
try except for white stripe effects, etc., and where color fastness 
requirements were not rigid, until the discovery of the special 
acetate silk dyes. 


1jJ. Foltzer, “Artificial Silk and Its Manufacture,’ Translation by T. 
Woodhouse, 3rd Edition, 1926. 

? Newport Chemical Works, Bulletin Series A, Number 3. 

8Wilson and Imison, J. Soc. Chem. Ind. 39, 322 (1920). 

*A. J. Hall “Cotton Cellulose,” 1924. 


J. M. Matthews, “Application of Dyestuffs,” 4th Edition, 1924. 
C. M. Whittaker, “Dyeing With Coal Tar Dyestuffs,” 2nd Edition, 1926. 


CHAPTER VIII 


THE DYEING PROPERTIES OF ACETATE SILK AND 
THE HYPOTHESES ADVANCED TO EXPLAIN THE 
PHENOMENON 


From our knowledge of the difference in the chemical consti- 
tution of acetate silk, as compared with that of the older rayons 
and natural textile fibers, which in the case of the rayons may 
very well be compared to the difference in constitution between 
olive oil and glycerine, we would certainly expect some difference 
in properties. However, when we come to consider the dyeing 
properties of acetate silk, we may even be surprised to find them so 
entirely different from those of the parent compound, cellulose, 
or the related rayons. 

Briefly, acetate silk has dyeing properties peculiar to itself and 
entirely different from those of any other commercial textile fiber. 
One of the chief drawbacks in the early attempts to dye it was due 
to the fact that everyone wanted to use the known common dyes 
upon it by the older ordinary methods of application. We cannot 
successfully dye cotton with acid wool dyes, nor wool with sub- 
stantive dyes, as a class. Therefore, as a new class of fiber, we 
may expect really satisfactory results only from a new class of 
dyes, developed especially for this new fiber, just the same-as we 
have certain other classes of dyes for the older known fibers of 
different constitution and properties. ~ 

Most textiles depend upon their color for much of their attrac- 
tiveness, and therefore a fiber or. fabric which may readily be 
dyed is in much greater demand than another fiber with the same 
textile, physical, and chemical properties, but which cannot be dyed 
in fast, brilliant, and attractive colors. There is no doubt what- 
soever that, during its early history, acetate silk was greatly handi- 
capped by its dyeing properties, or rather lack of them, in con- 
nection with the only dyestuffs then in use. While there is a cer- 
tain definite demand for fibers which are not dyed or stained in the 


: 104 


DYEING PROPERTIES 105 


ordinary dye bath, the actual consumption of fibers for this pur- 
pose, in pounds, is comparatively small for use as white effects 
only. Possibly the present wide interest in acetate silk is at least 
in part due to the attractiveness and fastness properties of the 
dyed fiber, and the ease of application of these fast colors by 
means of the new dyes developed particularly for this fiber. 


History of Acetate Silk Dyeing as Compared with Cotton Dyeing 


It is not difficult to recall that at one time in the history of 
cotton dyeing, the dyeing of cotton was in practically the same 
status as the dyeing of acetate silk in its early days or rather 
years. Today we are so familiar with the use of the direct cotton, 
vat, and other dyes that we are a little prone to forget some of 
the difficulties of former times. Before the discovery of the 
direct cotton dyes, the fast dyeing of cotton was possibly in an even 
worse state than was the dyeing of acetate silk before the discovery 
of the first special acetate silk dyes, the Ionamines. 

However, the chemists of today are much better equipped to 
combat a situation such as at one time existed in connection with 
cotton, and we have a much wider range of more or less suitable 
dyes for experimental purposes. But even so, before the dis- 
covery of the Ionamines in 1922, there was no special class of 
dyestuffs for acetate silk, no one class of dyestuffs which would 
give reasonably fast shades in all colors, and which could be used 
in wide combinations with other dyes on unions, etc. While certain 
commercial dyes and other compounds were applied to acetate 
silk with more or less success, probably only a few of these were 
wholly satisfactory for the purpose intended. 

From the early literature and patents upon the dyeing of acetate 
silk, it appears that the early acetate silks which presumably all 
consisted of primary cellulose acetates, were particularly refrac- 
tory in dyeing. With the advent of the later secondary acetates, 
more progress was made in the dyeing. Whether this was due to 
the change in the products themselves, or the accumulated knowl- 
edge and experience, is not clear. Very possibly both factors 
played a part, with the change in properties of the newer fiber in 
the leading role. A large part of the early dyeing troubles appear 


106 ACH TV Ada S Tas 


to have been due to the extreme difficulty in even thorough wet- 
tingout the fiber, on account of the high interfacial surface tension 
in all aqueous solutions, dye baths included. 

As would be expected, the difficulties in applying the older and 
then well-known dyes to acetate silk first resulted in a search for 
new and better methods of applying them to this new fiber. One 
of the first of these methods to be developed was by means of 
“swelling” agents, such as alcohol or other organic solvents in the 
dye bath. This led to the use of mineral acids in the bath, which 
caused a hydrolysis of the cellulose acetate, probably resulting in 
a product somewhat resembling the cellulose acetate produced 
by the Miles patent. This in turn appears to lead up to Mork’s 
saponification process of dyeing. 

The fact that all other textile fibers, including all of the other 
rayons, are turgoids, and as such swell in water or aqueous solu- 
tions, might lead us to expect good results by the swelling processes 
of dyeing acetate silk. In practice this process was never very suc- 
cessful on acetate silk. It was expensive, impractical, and unsat- 
isfactory, and is no longer used in dyeing. The saponification 
process permitted acetate silk to be dyed by the products commonly 
used in cotton and the older rayons, but it, too, is no longer used, 
except on special cases, such as in printing. However, it was a 
distinct advance in the art and was probably more satisfactory on 
the older primary acetate than the later secondary acetate silks. The 
early difficulties in dyeing acetate silk not only led to research upon 
new dyeing methods and special dyes, but also resulted in several 
attempts to manufacture a colored acetate silk fiber. This particu- 
lar development was discussed in Chapter III. 

The numerous difficulties encountered in dyeing acetate silk 
with the older, common, and better-known dyestuffs, even by the 
special methods, led to a great deal of research work and consid- 
erable study upon the subject of special acetate silk dyes by some 
of the most brilliant dye chemists in the world. As Celanese is the 
product of English research since the war, and the English manu- 
facturers in general appear to realize the value of chemical re- 
search in all lines, it is not surprising that practically all of the 
most recent and valuable advances in this field have been made in 


DYEING PROPERTIES 107 


England. In the production of these new dye products, the mem- 
bers of the research staffs of the British Dyestuffs Corporation, 
the Scottish Dyes, Ltd., and the British Celanese, Ltd., stand 
foremost as pioneers. In applying the results of this research, it 
should be remembered that possibly all of the work was done upon 
Celanese. While most of the results are also applicable to Lus- 
tron and Rhodiaseta as well as other varieties of acetate silk, 
there may be some minor variations or exceptions in certain in- 
stances. 


The Solution Theory of Dyeing 


As a result of the discovery of these new dyes and dyeing 
methods, a number of hypotheses have been advanced to explain 
just why certain products or classes of compounds are applicable, 
while others are not. As might be expected, all of this research 
and discussion has had a certain influence and value in connection 
with the dyeing of, and dyes for, all other fibers. At the present 
time the solution theory of dyeing acetate silk appears to receive 
the most support, but it is very probable that no one theory will 
satisfactorily explain the dyeing of any one fiber by all dyes, and 
that acetate silk is no exception in this respect. 

While the solution theory of dyeing acetate silk appears to 
favor the mechanical theory of all dyeing, it does not necessarily : 
prove it. In truth, the very fact that acetate silk is not dyed by 
the direct cotton and other dyes of the acid type has been used to 
assist the proof of the chemical theory of dyeing cellulose. Un- 
doubtedly more than one factor enters into the dyeing of acetate 
silk, just as it does into dyeing all other textile fibers. The high 
affinity of the color base of basic dyes and of compounds contain- 
ing the strongly basic amino group, as well as many other basic 
compounds, for acetate silk, which is certainly of an acidic char- 
acter, most certainly indicates that chemical factors play some, 
and possibly, the most important part. 

The fact that dyes which are soluble in ethyl acetate as a rule 
dye acetate silk does not prove that dyeing acetate silk is a solu- 
tion phenomenon. There is nothing to prevent the formation of 
compounds between the base of the dye and the acidic radicle of 


108 ACETATE SILK 


the solvent (ethyl acetate) in at least some of the cases. Without 
doubt where the solubility of the dyestuff in the fiber is greater 
than its (dyestuff) solubility in water, this solubility factor plays 
the important part in dyeing, but unless some form of chemical 
change or combination takes place, we would hardly expect these 
dyes applied by solubility alone to be fast to washing. In the case 
of the dispersol dyes, the method of solubilizing or dispersing the 
comparatively insoluble dyestuff is an important factor in its appli- 
cation and fastness, but this hardly explains the fastness of the 
strongly basic dyes on Lustron, the most acidic textile fiber of 
commerce. 

If dyeing acetate silk is entirely a solution phenomenon, why 
is it that very few compounds except those of a basic? character, 
or containing strongly basic groups, are soluble in acetate silk? 
A great many investigators appear to fear a chemical theory of 
dyeing any fiber, wool and silk included. They may look farther 
and do worse than a chemical theory in many instances. The fol- 
lowing is a very brief discussion of some of the recent papers 
upon the hypotheses advanced to cover acetate silk dyeing. 


Hypotheses 


Knoevenagel! was possibly the first to suggest the solution 
theory of dyeing acetate silk. He explained the absorption of 
phenols and amines by this fiber as a sort of “solid solution” in 
which the chemical and fiber took part. Possibly Knoevenagel’s 
discovery” of the fixation of the amines and phenols by acetate 
silk forms the basis of our present acetate silk dyes,” especially 
the Ionamines and other developed dyes. 

Green and Saunders,? in discussing the Ionamines, appear to 
favor the solution theory to some extent and compare the dyeing 
of acetate silk with that of hydrocarbon oils, such as paraffin or 
benzene, and mention the Sudan dyes, which color both acetate 
silk and hydrocarbon oils. They also state that benzene will re- 
move a certain amount of some colors from acetate silk and give 
an interesting experiment with Ionamine A in an aqueous-benzene 
mixture. 


* Also see Ellis, page 281. 
>’ See German Patent No. 198.008. 


Dy EING PROPERTIES 109 


On shaking an aqueous solution of Ionamine A with cold ben- 
zene, the water is yellow and the benzene colorless, but upon warm- 
ing and then shaking, the benzene eventually becomes yellow and 
the water nearly colorless. They explain this by pointing out that 
in the aqueous solution the aryl-omega-sulfonate is in equilibrium 
with the base-aldehyde-bisulfite, the balance being greatly in favor 
of the omega-sulfonate. In the presence of benzene, this balance is 
disturbed by the base passing into solution in the benzene. Ace- 
tate silk resembles benzene in that it absorbs little water when 
wetted. Also the interface, like that of benzene-water, acts as a 
semipermeable membrane, permitting the passage of the base but 
not of the aldehyde-bisulfite. 

The hydrolysis of the dye compound is thus greatly increased, 
since the basic compound is continually removed by solution in the 
non-aqueous solvent (acetate silk or benzene) while the semi- 
permeable character of the interface prevents the passage of 
aldehyde-bisulfite, to establish an equilibrium in the non-aqueous 
phase. Once within the acetate silk, the bases are firmly held 
(chemically?) as are most amino compounds; and hence show 
excellent fastness to soaping, washing, perspiration, etc. In the 
case of wool, which has a basic character and absorbs water, the 
unhydrolyzed Ionamine is probably taken up by the protein in the 
same manner as an acid dyestuff. This would tend to retard the 
hydrolysis of the Ionamine. 

Hall* points out that substances which form stable or water 
soluble salts, either with alkalis or acids, as for instance o-hydro- 
xybenzilideneacetone or aniline, are absorbed by the acetate silk 
but are largely removed by washing, and that the size and com- 
plexity of the dye molecule play a part in dyeing acetate silk. 
He writes that in a general way, the lower the molecular weight 
or the simpler the structure of the dyestuff, the more readily it 
dyes acetate silk and the more strongly it is retained. For instance, 
with Magenta (CopHeoN3Cl) which has a relatively high mole- 
cular weight, there is some difficulty in obtaining deep fast shades 
on Celanese. However more recent!? work does not appear to 
support his views regarding the importance of the molecular sim- 
plicity, as some of the products giving fast heavy shades'by the 


110 ACETATE SHlis 


dispersol method have a heavy, complex molecule, similar to that 
of the vat dyes. 

Meyer, Schuster and Bulow’ state that the dyeing of undeni- 
trated nitro silk (cellulose nitrate) proceeds by solution of the 
dyestuff in the fiber in the same manner as in dyeing acetate silk 
and that the same dyestuffs may be used. They found nitroani- 
line to be over a hundred times more soluble in this fiber than in 
water. 

In any discussion of the theory of dyeing acetate silk, the role 
of the sulfonic acid groups in dyestuffs must not be overlooked. 
As is well known, the sulfonic acid group is widely used in connec- 
tion with certain classes of organic compounds, particularly acid 
dyestuffs, to confer solubility in water. While it is certainly a 
very great help in solubilizing these compounds in water, it does 
not increase their solubility in organic solvents, such as benzene or 
ethyl acetate, and in fact usually reduces it considerably. This 
fact also holds good with acetate silk and appears to play an im- 
portant part in any attempt to apply the sulfonated dyes to this 
fiber. This may appear to support the solution theory of dyeing; 
however, the strongly acidic character of the sulfonic group, in 
conjunction with the acid character of acetate silk, may have some 
significance to those who look for a chemical theory. As might 
be expected, in the case of acetate silk the adverse influence of the 
sulfonic group may be overcome to some extent by the presence of 
certain other groups, usually of a basic character. | 

Carboxylic acid groups also have the property of solubilizing 
certain relatively insoluble organic compounds in water, but does 
not reduce their solubility in organic solvents, as in the case of 
the sulfonic groups. For this reason the carboxyl group has been 
used in place of the sulfonic group, to solubilize certain dyes for 
acetate silk with considerable success. Here again the less acid 
character of the carboxyl group may serve to explain a point in 
the chemical theory of dyeing acetate silk. Nitro groups may also 
be present in acetate silk dyes without detrimental effects. 

The stability of the sulfonated dyes may also play a part in their 
lack of dyeing affinity for acetate silk. Greenhalgh® points out 
that in some instances the staining of acetate silk by acid and 


DYEING PROPERTIES ale hal 


direct cotton dyestuffs is due to a selective absorption of the base 
of the dyestuff by the acetate silk. He states that in some in- 
stances the affinity of the acetate silk for the base is sufficient to 
cause the withdrawal of the base from the dyestuff molecular 
complex, thereby giving a partial decomposition of the dyestuff. 
This certainly does not entirely support the solubility theory of dye- 
ing acetate silk only. While the acetate radicle of the fiber may be 
able to withdraw the basic group from certain dyestuffs under 
some conditions, we would hardly expect it to be able to overcome 
the affinity of the strongly acid sulfonic group for the dyestufft 
base in every instance. It is interesting to note that Prof. Hibbert 
states that the basic dyes are possibly attached only to the acetate 
groups in acetate silk. 

Greenhalgh also points out that the dyeing of acetate silk by the 
commercial magenta dyestuff is due entirely to the absorption of 
the magenta base, and not of the salt of the base. Very probably 
this statement holds true for many of the basic dyes. The fact that 
they are retarded in the dye bath by the presence of either acetic 
acid or sodium chloride, both of which would tend to diminish — 
the amount of free color base in the dye bath, indicates that this 
statement is correct. The dyeing of acetate silk by means of 
bases in colloidal solution (dispersol method) also supports this 
statement. 

According to Caille®:1® the affinity of the basic dyes for the 
cellulose esters (acetate and nitrate) appears to be largely de- 
pendent upon the amount of combined sulfuric acid present in the 
ester. He gives tables showing that the percentage of basic dye- 
stuff fixed by the cellulose derivatives varies with the percentage 
of combined sulfuric acid, but this variation is not proportional, 
and in the case of cellulose acetate, the combined acetic acid 
plays a secondary part in the fixation of the basic dyestuff. With 
dyestuffs such as Methylene Blue and Auramine on acetate 
silk, the combined sulfuric acid is the main factor, even where 
the acid has been neutralized with calcium. He believes that the 
oxycellulose present with the cellulose esters in the fiber also in- 
fluences the basic dyestuff affinity, but to a considerably smaller 
extent than the combined sulfate radicles. Even in denitrated 


112 ACETATE SILK 


nitro silk the sulfate esters play a very important part. ver 
Caille does not believe that the dyeing of the cellulose esters is a 
chemical phenomenon, mainly for the reason that the amount of 
dyestuff fixed by the ester is not proportional to the total sul- 
furic acid content.° 


Surface Fixation of Dyestuffs 

Paneth and Radu’ report that while cuprammonium and nitro 
silks are stained throughout, even when the absorption of basic 
dye has not attained its maximum, sections show that acetate silk 
is stained only externally by Methylene Blue. Their experiments 
upon one particular variety of acetate silk, probably Celanese, 
shows the absorption of Methylene Blue on this fiber to be of the 
same order as that by the diamond. In other words it is entirely as a 
monomolecular layer and may be used as a method to measure the 
surface area of the acetate silk. Ginsberg® states that it took 
almost four months to completely dye an acetate silk, variety not 
stated, with Methylene Blue. 

Meyer, Schuster and Bulow’, and Meyer® confirm this work 
regarding the surface fixation of certain basic dyes on acetate silk 
in the form of a monomolecular layer and explain it on the basis 
of Langmuir’s explanation of the layer of soap on water. Lang- 
muir shows how the water-soluble groups of the soap-fatty acid 
molecule, i.e., the carboxyl group, actually penetrates the water. 
In the same manner they explain that the aromatic portion of the 
basic dyestuff is soluble in acetate silk, while the salt-like group, 
such as ammonium hydrochloride, which is itself soluble in water, 
does not penetrate the fiber. If Langmuir’s theory is correct in the 
case of soap and water, and it very probably is, very possibly the 
same explanation may hold good to some extent for the applica- 
tion of certain basic dyes to acetate silk. 


From a study of the known properties, composition, etc., of Lustron 
and Celanese, it appears probable that Lustron may consist of the pri- 
mary cellulose acetate while Celanese consists of secondary acetate. The 
dyeing and non-blinding properties of the former (Lustron) suggest that 
it may also contain some neutralized sulfuric acid groups. This may ac- 
count for its high affinity for the basic dyestuffs, in which it surpasses 
all other textile fibers. Celanese, on the other hand, contains some hy- 
droxy groups, similar to those present in the regenerated cellulose rayons, 
which accounts to a large extent for the differences in the dyeing prop- — 
erties of the two ester fibers. 


DYEING PROPERTIES 113 


Dyewmg With “Assistants” 


In applying basic dyes with “assistants,’’* the aromatic portion 
of the basic dye unites with the mordant or assistant to form a 
compound which is more soluble in, or has more affinity for, the 
acetate silk than the complete dyestuff alone. This is indicated 
by shaking an aqueous solution of a basic dyestuff with ethyl 
acetate, when, upon the addition of the assistant, the ester is 
deeply colored. While the dye-assistant compound enters and 
dyes the interior of the fiber, the surface action probably also 
takes place simultaneously to some extent, the process of solution 
and absorption occurring one upon the other, to give deep shades 
of increased fastness. 

Meyer, Schuster and Bulow? investigated the dyeing of acetate 
silk by means of weak organic bases, on the basis that most of the 
compounds used in dyeing this fiber come in this classification, as 
for instance: (4) Various nitroamine compounds (derivatives of 
nitroanilines), such as Yellow 3G Paste for Acetate Silk (Bad- 
ische), Celatene and S. R. A. Yellow, etc., (B) Numerous 
aminoazo derivatives, such as Yellow R Paste for Acetate Silk 
(Badische), and Azonine Direct Yellow 2R (Cassella) ; (C) Am- 
inoanthraquinones such as Orange Paste, Rose R Paste, Red- 
Violet Paste, and Blue Paste for Acetate Silk (Badische). 

Along with Meyer,® they support the solution theory of dyeing 
acetate silk on the basis of its fixation of o-nitroaniline, a typical 
weak organic base. The amount of this base fixed when equili- 
brium is reached, shows that the distribution coefficient between 
water and acetate silk is a constant for all concentrations. The 
color of the treated fiber is uniform throughout its cross-section 
which shows that it is not an adsorption process. They also point 
out the interesting fact that nitroaniline cannot be displaced from 
acetate silk by tetralin, in which it is very soluble; and that acetate 
silk remains colorless in solutions of o-nitroaniline in tetralin. 
Dyeing or stripping only occurs in the presence of water, the 
function of which is not understood. Is it not possible that the 
hydrolysis of nitroaniline in water, with the resulting presence of 


"See Chapter X. 


114 ACETATE Siik 


certain active groups, may explain that function of the water? 
They state that the solution theory is further substantiated by the 
fact that all substances which are removed from water by ethyl 
acetate, are also able to penetrate acetate silk, whether they dye 
it or not. This applies to the sulfonated dyes, such as Azoflavine 
and the Cellit Fast dyes. 

Kartaschoff! points out the fact that as the bases and basic dyes 
are electropositive, their affinity for acetate silk suggests that it is 
electronegative; and then he proceeds to confirm this by electro- 
lyzing cellulose acetate in a fine state of division and in the form 
of a skein. The acetate silk dissolves slowly at the negative elec- 
trode and is reprecipitated unaltered at the positive pole. The 
phenomenon, therefore, is one of electrophoresis rather than 
electrolysis. However, as the dyeing is not accelerated by the use 
of an electric current, he believes that the electric charge does not 
play an important part in dyeing this fiber. 

He also studied microscopically the progress of the dyeing of 
acetate silk, using aminoanthraquinone derivatives (Celatene dyes), 
and believes the process to be a simple solution of the dyestuff in 
the fiber, important parts being played by temperature and the 
presence of water. Crystals of the dye collect on the surface of 
the fiber first, and then dissolve gradually into it. On placing dry 
acetate silk fibers and solid dry dyestuffs in contact with each other 
for several days at 60° C. (140° F.), a permanent dyeing resulted 
which proves to him that the dyeing of acetate silk is a simple 
solution effect in which water may play a useful but not an indis- 
pensable part. 

In a later paper, Kartaschoff™ studied the acetate silk dyeing 
theories by colorimetric measurements of the initial and final con- 
centrations of various purified direct cotton dyes in dye baths con- 
taining Celanese. He found that in many cases, as for instance 
with the phthaleins, the difference between the initial and final 
concentrations of the bath does not give a correct value for the 
amount of dye taken up by the fiber, since there is a precipitation 
of dye on the fiber surface, which makes difficult any sharp dis- 
tinction between colloid suspensions and macrocrystalline sus- 
pensions. His results are opposed to the theory of Clavel, but 


DYEING PROPERTIES 115 


support the theory that the dyeing of acetate silk is a purely phy- 
sical phenomenon due both to solution of the dyestuff in the fiber 
and to absorption on the surface by means of groups such as the 
hydroxyl and amino groups. 

Contrary to Clavel’s theory, he found that if the free color acid 
of a dyestuff is less soluble in water than its sodium salt, as for 
example in the case of Eosine I, Toluylene Orange, Acid Ponceau, 
etc., the free acid and its ethyl ester have greater dyeing powers 
for acetate silk than the sodium salt. Thus much deeper shades, 
though not altogether fast to washing, may be obtained by dyeing 
in a bath containing the free color acid and then passing the goods 
through a sodium bicarbonate bath, than by dyeing in the ordinary 
way. With water soluble dyes it is a general rule that the more 
soluble the dye is in the water, and the smaller its partition 
coefficient between water and ethyl acetate, the less its affinity for 
acetate silk (an acetate of a higher alcohol). It is an approxi- 
mate rule, that whether the dye is soluble in water or not, if in 
comparison with its molecular weight the dyestuff is easily soluble 
in ethyl acetate, it will dye acetate silk effectively. 

The size of the dye particle is not important, as is shown by 
dry dyeing, and affects only the rate of diffusion into the interior 
of the fiber. In the case of insoluble dyes it is shown, again con- 
trary to Clavel’s view, that a molecular dispersion will not dye the 
acetate silk; but the finer the suspension, the more rapid is the 
solubilization of the dye. With colors developed on the acetate 
silk fiber, such as the black obtained on treating the fiber with di- 
anisidine, diazotizing, and coupling with B-hydroxynapththoic acid, 
it is probable that the molal solubility of the dyestuff in the fiber is 
less than that of the first component, so that the fiber becomes su- 
persaturated with the dyestuff, which crystallizes out in the interior 
of the fiber. Owing to the insolubility of the azo color in water, 
it is not removed by washing. This crystallization of the dyestuff 
in the fiber undoubtedly accounts for the blinding or loss of luster 
which occasionally occurs in acetate silk during the development of 
such colors, in which case the color crystals are sometimes visible 
under the microscope.1? 


116 ACETATE SILK 


Clavel® studied the effect of various groups or radicals in the , 
dyestuff molecule upon its affinity for acetate silk, and theorized 
that the affinity of dyestuffs for acetate silk is due to the presence 
of certain active groups, which, in the absence of sulfonic acid 
groups or if preponderating over, say, one sulfonic group present, 
are capable of dyeing acetate silk. He attempted to classify the. 
dyes and radicles on this basis in the order of their numerical 
presidence regarding their basic or acid influence on the dye mole- 
cule; but so many factors, such as the orientation of the radicle 
in the molecule, the state of aggregation, etc., enter into the matter, 
that it is rather difficult to make a general rule covering the affinity 
of dyes for acetate silk. 

He states that dyes of any class containing hydroxyl, amino, 
imino, imido, nitro, nitroso, isonitroso, acidylamino, or azo groups, 
and either no sulfonic acid groups, or not more than one sulfonic 
group together with two or more of the above groups, are suitable 
for dyeing acetate silk. Recent articles in the Revue Generale 
des Matieres Colorantes have extended and modified Clavel’s origi- 
nal theory. Frank also studied this problem and found that the 
position (orientation) of the sulfonic group in the molecule is a 
very important factor. 


The Dye in the Fiber 


Haller and Ruperti!? report some interesting work upon the ; 
orientation of coloring matters within acetate silk and other fibers. 
When acetate silk is dyed at low temperatures with Para-Red, 
it has a yellowish shade, the dye being uniformly distributed within 
each fiber. After immersion in hot or boiling water, the shade be- 
comes redder and the dye agglomerates into larger particles. 
Similar results are obtained, although with greater difficulty 
(steaming under pressure is necessary), when Para-Red is ob- 
tained from naphthol AS instead of B-naphthol, or when aminoa- 
zobenzene is used instead of p-nitroaniline. 

Similar changes are observed in nitro silk dyed with the same 
dyes and also with Indigo, Thioindigo Red, and Indanthrene Blue. 


© See British Patents No. 182,830, No. 182,844, No. 226,948, and German 
Patent No. 355,533. 


DYEING PROPERTIES 11% 


Nitro silk dyed cold with Naphthylamine Claret (a-naphthylamine 
coupled on the fiber with B-naphthol) contains the dye evenly dis- 
tributed. When heated in water under one atmospheric pressure 
the dye agglomerates slightly without change of shade, but when 
heated for a prolonged period in boiling water or subjected to a 
short steaming under six atmospheres pressure, agglomeration be- 
comes complete, the dye migrates towards the surface of each fiber 
and is deposited there as well-defined crystals which may be re- 
moved by washing and pressing, the fibers being thereby decolor- 
ized. Thioindigo Red dyed on nitro silk behaves similarly. Chrome 
Yellow, from lead acetate and a dichromate, dyed on nitro silk, 
is at first evenly distributed, but after steaming under four atmos- 
pheres pressure, agglomerates, and becomes orange, even in the 
absence of alkali, although no migration of the pigment occurs. 

Similar changes are observed by steaming dyed cotton, except 
that the agglomerated dyes migrate to the boundaries of the lumen 
in each fiber as well as to the cuticle, the migration, change of 
shade, and condensation or crystallization of the particles of dye 
being favored by prolongation of the steaming or rise of tempera- 
ture. Vat dyes, Indigo and Thioindigo Red easily, and Indan- 
threne Red 5GK, Indanthrene Brilliant Violet RK, and Indan- 
threne Blue RS with greater and increasing difficulty, crystallize 
and migrate within cotton fibers to the lumen and cuticle when 
steamed, accompanied by a change in shade. Uncertain results 
are obtained by steaming cotton dyed with direct dyes. 

Alizarin Red dyed on cotton mordanted with aluminum acetate 
is evenly distributed within each fiber, but when steamed for an 
hour under a half atmosphere pressure the pigment agglomerates 
and migrates to the lumen and cuticle. That deposited near the 
cuticle is removed by washing with water, the fiber being left color- 
less. Under similar conditions the presence of Turkey-red oil 
considerably retards the agglomeration and migration, and the 
dye which migrates to the cuticle cannot be removed by washing. 
The decrease in fastness to rubbing produced by steaming cotton 
dyed with indigo is due to migration of the dye to the cuticle of 
each fiber. 

Haller!? reports work of a similar nature upon the color changes 


118 ACETATE SILK 


of the blue and violet benzidine dyes on cotton, wool, and acetate 
silk, especially on touching the dyed cotton with a hot iron. His 
experiments are stated to confirm the view that these dyes form 
colloidal solutions of different degrees of dispersion, the larger 
particles coloring the cotton fiber blue, the smaller corinth-red. 
Solutions of a low degree of dispersion are particularly sensitive 
to temperature changes or to variations in the medium employed. 
Thus, in hot dye baths, wool and cotton are dyed red by aqueous 
solutions; but on cooling, the color on the bottom becomes blue- 
violet. Alcoholic solutions hardly affect wool but dye cotton a 
permanent corinth-red. 

The effect of touching the dyed cotton with heated metal is to 
increase the degree of dispersion of the dye in the fabric, with a 
change of color from blue to red. The addition of hydrazine 
hydrate to aqueous Diamine Blue 3R solution causes a similar 
change, and the solution will then dye cotton corinth-red. The 
absorption of the dyes by fibrous alumina and barium sulfate 
indicates a fixed relationship between the degree of dispersion of 
the dyestuff and that of the absorbent. The surface of the ab- 


sorbent plays a decisive part also when fibers are used, for swelling | 


causes inner micellar surfaces to come into play, the difference in 
the sizes of these accounting for the different behavior of different 
absorbents. 

Wool and acetate silk, after swelling, have larger inner surfaces 
than cotton. Thus an alcoholic solution of Diamine Blue 3R 
causes swelling of acetate silk and dyes it corinth-red. After 
saponification with sodium hydroxide, washing the fiber, and acidi- 
fying, the color changes to blue, showing that during saponifica- 
tion the inner structural conditions are changed. The reddening of 
blue-dyed cotton is also produced by desiccation over sulfuric 
acid, but to a less extent than by heating. The observed color 
changes on heating, and drying may thus be connected with dehy- 

dration and simultaneous increase in the degree of dispersion of 
the dyestuff within the fiber. 


Basic Dyes and Bases on Acetate Silk 


Among the older dyes, more products belonging to the basic 
group are applicable to acetate silk than those of any other one 


Se 


ns 
ly tt tet bi at nin ed 


DYEING PROPERTIES 119 


group. The first acetate silks, consisting of primary cellulose 
acetate, were of such a nature that it was almost or quite impos- 
sible to dye them level and deep shades with even these dyes. 
Apparently the basic dyes were only taken up substantively after 
drastic treatment to alter or swell the fiber. Of our present ace- 
tate silks, Lustron, which is a comparatively highly acetylated 
cellulose, has a greater affinity for the strongly basic dyes than any 
other known textile fiber. Even when applied without a mordant 
on Lustron, some of these dyes show a greater fiber affinity and 
fastness than upon any other known fiber. As might be expected, 
the affinity of Celanese, which is not as highly acetylated as Lus- 
tron, for the strongly basic dyes is considerably less than that of 
Lustron. This difference in affinity for certain basic dyestuffs 1s 
sufficient under certain conditions to give medium shades on 
Lustron, while the Celanese remains white in the same dye bath. 

The free color bases of many basic dyes may also be applied to 
acetate sill from colloidal suspensions, as in the dispersol method 
of dyeing. When applied in this manner, they frequently have a 
greater affinity for the acetate silk fiber than when applied as the 
aqueous solution of the commercial basic dyestuff. In fact many 
substances in colloidal solution have a high affinity for acetate 
silk, and this has formed the basis of the application of many 
of the new dyes specially developed for application to acetate silk 
by the dispersol process. In some cases products which have no 
affinity for the acetate silk fiber when they are in true solution, 
have a high affinity for it when they are in colloidal solution. 
From our study of the theory of acetate silk dyeing, this might be 
expected for two reasons: first, on account of the decreased solu- 
bility of the free color base in water; and, secondly, due to the 
lack of any retarding effect of the acid or acidic radicle used for 
solubilizing the ordinary basic dye. Also it leaves the color base 
free to combine with any acidic radicles of the acetate silk. For 
this reason we may expect these free color bases to have a better 
penetration and less “skin” effect, as they are not held on the 
surface by the acidic radicle of the dyestuff molecule.* 


£ See British Patent No. 255,962. 


120 ACETATE. SIE 


Mordanting 


Acetate silk has no affinity for the usual soluble salts of the 
metals used in mordanting the other textile fibers, such as chro- 
mium, aluminum or iron; nor will it take up their hydroxides to 
any extent, either as precipitates or as colloidal solutions. However, 
as discussed under the mordants,® it has recently been found that 
it does have an affinity for certain special salts of the mordanting 
metals, such as the thiocyanates, but these particular salts had not 
previously been used in mordanting, and the process is probably 
not yet highly successful on a commercial scale. It has no 
affinity for the tannins or other usual cotton mordanting agents. 
In the application of some basic dyes to acetate silk, certain metal- 
lic ‘salts, such as zinc nitrate, tin, barium, and magnesium chlor- 
ides are used, as mentioned under ‘‘Assistants,’" but these are not 
true mordants. Certain colors, such as the Gallocyanines,? may 
be after treated on the fiber with metallic salts, such as chromium, 
to give colors of increased fastness. 


Direct Cotton Dyes 


Acetate silk has no affinity for most of the direct cotton dyes; 
however, there are a few exceptions, which will be discussed with 
the other dyes of this class. In fact cellulose acetate resists about 
60 per cent of the direct cotton dyes to such an extent that 
patents were, at one time granted on a method of resisting cotton 
by means of acetylating the outer layer of the cellulose fibers. A 
product known as “Bayko” yarn also appears in the literature. 
This yarn was prepared by coating a cotton thread with a layer 
of cellulose acetate. Bayko yarn was used as a resist-thread 
effect, and even today the widest use of acetate silk is in resist- 
thread effects, either white or in contrasting colors, in cotton 
goods. In many cases where the acetate silk is stained by direct 
cotton or acid dyes, this staining is due to the presence of basic 
impurities or shading dyes. 


® See Chapter XII. 
" See Chapter X. 


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he hl ae, 


ee es 


a ee ee eee 


DYEING PROPERTIES 121 


Acid and Mordant Dyes 


While acetate silk has no affinity for the acid dyes as a class, 
largely due to the influence of the sulfonic acid group, there are a 
few exceptions where the other groups present have sufficient influ- 
ence to overcome the effect of the sulfonic group. It also has an 
affinity for many dyes and other compounds containing amino, 
alkylamino, azo, hydroxyl, nitro and/or ketonic groups, and ab- 
sorbs certain hydroxyazo dyes which contain no sulfonic groups, 
such as Alizarin Yellow R (p-nitrobenzeneazosalicylic acid) and 
Metachrome Brown B (2-hydroxy-3, 5-nitrobenzeneazo-m-phenyl- 
enediamine). Recently some special acetate silk dyes have been 
developed which are solubilized by means of carboxylic, arsenic, or 
other acid groups (other than sulfonic groups), and these belong 
to the acid classification. Some mordant dyes are also applicable to 
acetate silk and many of the slightly soluble products applied by the 
dispersol process might come under the acid and mordant dye clas- 
sification if they were not applied by the dispersol method. As the 
acid and mordant dyes are applied to acetate silk by methods 
similar to those used for the direct dyes on cotton, they offer a 
tapidly growing and very interesting group for acetate silk. 

By means of the saponification process of dyeing, which is no 
longer used except in printing, etc., it is possible to apply the 
direct cotton and, in fact, almost every other class of dyes used 
upon cotton or the older rayons to acetate silk. Possibly none of 
the sulfur dyes have a direct affinity for normal acetate silk, but 
they may be applied to the saponified fiber. Some of the vat 
dyes have an affinity for acetate silk, especially when applied by the 
dispersol method, but practically all of the vat dyes are applicable 
to the saponified fiber. The aminoanthraquinone dyes have a 
special and unexpected affinity for acetate silk, especially from a 
colloidal solution.' 


Developed Colors 


Acetate silk has an affinity for many of the components com- 
monly used for the production of developed or azoic colors on the 
cotton fiber, and these may be used for the same purpose on ace- 


i See the Duranol and Celatene dyes. 


122 ACIGCATIIE Silk 


tate silk. It has a very decided affinity for many amino com- 
pounds, particularly the primary amino bases, such as p-nitro- 
aniline, aminoazobenzene, benzidine, dichlorobenzene, o-anisidine, 
p-aminodiphenylamine, etc. These may be applied as aqueous 
solutions of their hydrochlorides, as [onamines, as an aqueous sus- 
pension prepared by netitralizing the hydrochloride in the aqueous 
dye bath, or by the dispersol process. They are then diazotized 
and developed on the fiber to give a variety of very fast colors, 
ranging from pale tints to black. This fact led to the development 


of many special products for use especially upon acetate silk, and 


these will be considered in detail under the developed dyes and the 
Ionamines. While the developed colors are not used on acetate 
silk at present to so large an extent as formerly, they are still 
used to some extent, particularly for heavy shades of the highest 
fastness properties, especially black. In fact, products which 
may be diazotized and developed are found in almost all classes of 
dyes used upon acetate silk. 

The application of the special acetate silk dyes, the lonamines, 
and dispersol type of dyes, as well as the theories evolved during 
the development of these products, will be discussed in connection 
with these dyestuffs. While the Ionamines and the dispersol type 
of dyes are especially well-known among the dyes for acetate silk, 


the advantages of some of the other special acetate silk dyes, such , 


as the Setacyl Direct dyes, should not be overlooked. 

Since the advent of the many new special acetate silk dyes, the 
older dyes are not now so generally used on this material, or even 
on the acetate silk in unions, in which acetate silk takes only a 
minor part. However, they are always used upon the other fibers 
accompanying the acetate silk in these unions and on all materials 
containing acetate silk effects. Therefore, while the new dyes are 
now used almost but not quite exclusively upon acetate silk in 
every form, a complete knowledge of the dyeing properties of the 
older dyes upon acetate silk is essential in handling unions or 
materials containing it. Also in dyeing colored acetate silk effects 
in various materials, where the acetate silk effect plays only a 
minor part, the older dyes are still frequently used. 

The foregoing fully shows that the dyeing properties of acetate 


DYEING PROPERTIES | 123 


silk are peculiar to this one fiber and that we may expect satis- 
factory results only from products and methods of application 
developed particularly for this one fiber. With the recent ad- 
vances in dyes for, and methods of application to, acetate silk, 
it is just as easy today to obtain fast, brilliant, and pleasing shades 
on this fiber as on any other, provided only we use the same care 
in selecting the dyestuffs and in applying them that we use in 
dyeing the other fibers. Celanese and Lustron differ in many 
minor points in their dyeing properties, and probably the other 
English and European acetate silk fibers may each have its own 
individual characteristics and variations; but, as acetate silks and 
distinct from all other textile fibers, they are all dyed in the same 
general way and by the same products. For instance, the dye- 
ing properties of Rhodiaseta are similar to those of Celanese 
and Lustron, in that it resists the direct cotton and sulfonated 
dyes, but takes the Ionamines, all of the dispersol type dyes, the 
Cellutyl, Cellit, Setacyl, Setacyl Brilliant, Setacyl Direct, and other 
special dyes for acetate silk. While Rhodiaseta is not so well 
known in America and to the author as are Lustron and Celanese, 
it is just as suitable for use as white or contrasting color effects in 
combination with cotton, wool, and other fibers, as the other 
brands of acetate silk, and it is widely used for this purpose in 
France and neighboring countries. 


Phototropism 


Before leaving the theoretical discussion of acetate silk dyeing, 
it may be well to mention a difficulty encountered in the search for 
dyestuffs particularly suitable for use on acetate silk. When ap- 
plied to acetate silk, many colors appear to be subject to “photo- 
tropism,” a rather newly discovered property of some dyestuffs 
which is found almost only on acetate silk and which is not usually 
found in the same color on other fibers. Phototropism is the 
property of a color on the fiber to change in color or shade under 
certain lighting conditions. For instance, if the dyed acetate silk 
is shielded from the light for a few minutes, on removing the 
shield, the color is lighter beneath where the shield covered, but 
darkens in a short time until it matches the surrounding color. 


124 ACETATE SIE 


This difficulty was encountered in the development of both the 
Ionamines and the dispersol type of dyes. While it is rare on 
other fibers, it is not entirely unknown, as for instance in the case 
of Fast Light Yellow on wool. 

Green and Saunders? report that nearly all of the yellow amino- 
azo bases show this property on acetate silk, and though varied by 
substitution in the benzene nucleus, no definite relationship be- 
tween the position of the substituents and the occurrence of photo- 
tropism can be traced. Apparently the greener the shade of the 
yellow, the more pronounced is its phototropism. The difficulty 
usually disappears when orange shades are reached. 

The cause of phototropism in certain azoic dyes on acetate silk 
has never really been satisfactorily explained, but Greenhalgh™ 
compares it with the desmotropism of p-nitrosophenol. In the 
case of p-nitrosophenol, under certain conditions the compound is 
white and under others it is yellow. Analysis of the yellow prod- 
uct shows that it is not p-nitrosophenol but is quinone oxamine. 
This change in both color and constitution is due to the transposi- 
tion of a hydrogen atom in the molecule from one group to another. 
Greenhalgh suggests that there may be a similarity between the 
phototropy of certain azo dyes on acetate group and the desmo- 
tropy of p-nitrosophenol. It is well known that acetate silk has 
a high affinity for amino groups, and, while nitrogen is usually 
considered rather inactive, the azo coupling undoubtedly has con- 
siderable activity. In the case of certain azo dyes on acetate silk, 
the position or connections of this azo group may possibly be so 
shifted or altered, by the presence or absence of light, as to cause 
phototropism. 

Phototropism is shown not only by the azo dyes on acetate silk, 
but also by some other nitrogen-containing groups, such as amino 
and nitro groups, and in certain cases under some conditions, it 
appears to be impossible to completely diazotize some amino com- 
pounds on acetate silk, which probably may be due to the high 
affinity of this group for the acetate silk fiber. This certainly looks 
as though the chemical affinity of the acidic acetate silk fiber for 
the basic amino group of these dyes plays some part in dyeing this 
fiber. 


DYEING PROPERTIES 125 


References 


1K. Knoevenagel, Kolloidchem. Beithefte 13, 233 (1921). 

2K. H. Meyer, C. Schuster and W. Bulow, Texrtilber. 6, 757-8 (1925). 
oe Green and K. H. Saunders, J. Soc. Dyers and Colourists 39, 10-6 

Zan 

*A. J. Hall, Textile Colorist 46, 154 (1924). 

5K. Greenhalgh, Dyer and Calico Printer 55, 106 (1926). 

6A. Caille, Chim. et Ind. 15, 61-4T (1926). 

7Paneth and Radu, Ber. 57, 1221-5 (1924). 

8]. Ginsberg, American Dyestuff Reporter 12, 652 (1923). 

°K. H. Meyer, Textilber 6, 737-9 (1925). 

10 V7. Kartaschoff, Helv. Chim. Acta 8, 928-42 (1925). 

1. Kartaschoff, Helv. Chim. Acta 9, 152-73 (1926). 

12 Haller and Ruperti, Cellulosechem 6, 189-92 (1925). 

1 R, Haller, Kolloid-Z. 38, 248-53 (1926). 

“4B, Greenhalgh, Dyer and Calico Printer 55, 146 (1926). 

1K, H. Meyer, C. Schuster and W. Bulow, Melliand’s Textilber. 7, 
29-30 (1926). 

16 A Caille, Chim. et Ind. 15, 189-92 (1926). 

178, M. Rowe, J. Soc, Dyers and Colourists 42, 207-8 (1926). 


CHAPTER IX 


THE METHODS USED IN DESIZING, SCOURING, 

BLEACHING AND TINTING ACETATE SILK. DEGUM- 

MING TRUE SILK IN THE PRESENCE OF ACETATE 
SILK 


Just as in dyeing all other fibers, a thorough wetting-out and 
cleansing of the acetate silk is absolutely necessary in order to 
obtain the best results in either bleaching or dyeing. Where the 
yarn has been sized, a thorough removal of all sizing materials is 
of course the first step in the process. A number of desizing and 
scouring methods and formulas have been suggested and used on 
acetate silk with just as varied results. Where the material to be 
scoured contains another fiber in combination with the acetate 
silk, this serves to complicate the process somewhat. From the 
foregoing study of the properties of the acetate silks it is very 
evident that the scouring process for Lustron may be somewhat 
more severe than that for Celanese or Rhodiaseta. Yet even on 
Lustron we cannot employ either strong or caustic alkalies, and 
undoubtedly much better results, as regards the textile properties 
of the fiber, are obtained by using mild detergents at medium 
temperatures. 

The manufacturers? of Celanese strongly caution against the use 
of either high temperatures or free alkali in any process on Celan- 
ese. However, Grimshaw’ states that Celanese will not lose its 
luster on treating it for 30 minutes with as much as four ounces of 
soda ash per gallon of water, at temperatures below 80° C. (176° 
F.). The Lustron Company state that their product will withstand 
the usual natural silk boil-off and that as much as 5 per cent of 
sodium carbonate may be used in fulling at temperatures below 
60° C. (140° F.). A very important thing to remember in scour- 
ing, bleaching, dyeing, or in any other wet process on acetate silk, 
+s that it should be handled like true silk, rather than like cotton. 
This is particularly important in skein scouring, dyeing, or other 


126 


ume METHODS USED 127 


wet processing of fine denier yarn, otherwise serious trouble may 
be experienced in winding. 

In scouring Rhodiaseta, as well as in dyeing it, the same care, 
as regards the temperature and alkalinity of the bath must be 
exercised as in handling Celanese. The luster and brilliancy of 
Rhodiaseta may be impaired considerably by scouring above 80° 
C. (176° F.), or in the presence of alkalies, such as sodium car- 
bonate, in high concentrations, unless special precautions are taken 
as described later. 

It is of course obvious that in no operation on any variety of 
acetate silk or on any material containing it, can we use any process 
similar to kier boiling. This of course means that on cotton- 
acetate silk unions, or even cotton goods containing acetate silk 
effects, the cotton must be scoured by a less drastic method than 
kier boiling. Grimshaw! found that such sizing materials as 
modified corn starch, Celanese size, gelatin, potato starch, or a 
combination of gelatin, starch, and glucose, were much easier to 
remove from the Celanese of Celanese-cotton unions, than from 
the cotton. 

The usual Celanese-cotton scour, as given in Method No. 6 
below, but for two hours, removes the sizing materials completely 
from Celanese; but the iodine test shows starch still present on the 
cotton in sufficient quantities to prevent a good white on bleaching 
by the usual methods. Even a soap-and-soda-ash scour, such as 
used on viscose-cotton unions, but at 80° C. (176° F.), failed to 
completely remove the size from the cotton. For this reason he 
recommends the use of an enzyme steep as in Methods No. 1 or 
No. 3, before scouring. Method No. 2 is very similar. The goods 
should then be scoured for one hour by his modification of Method 
No. 6, as given in Method No. 7. When desized and scoured by 
these methods, a good white is obtained upon both the cotton and 
Celanese by bleaching as in Method No. 15, either with or without 
acetic acid. The antichlor treatment, as given in Method No. 18, 
may be used to advantage. Grimshaw! also states that the sizing 
materials may be removed by Method No. 4. 

Where gelatin is a constituent of the acetate silk sizing mixture, 
care must be taken to see that all of this sizing material is removed 


128 ACETATE SUK 


before attempting to dye the material.° Gelatin is a protein and as 
such has dyeing properties somewhat similar to those of wool. 
The dyeing properties of acetate silk approach those of wool more 
nearly than those of any other fiber in many respects. For this 
reason many of the acetate silk dyestuffs dye wool and gelatin, 
with the result that if the gelatin sizing material is not thoroughly 
removed before the rayon enters the dye bath, quite unexpected 
results, as to color, are frequently obtained. One of the best 
methods of removing gelatin is to first soak the sized rayon in cold 
water for some time and then warm up the bath gradually, so 
as to bring the swollen gelatin into solution. 

No matter what process is used in desizing, scouring, or bleach- 
ing acetate silk, care must be taken to avoid the hydrolysis or 
saponification of the ester, which results in a complete change of 
dyeing properties and affinities, with the consequent uneven shades. 
A discussion of the properties of this saponified or partially sapont- 
Ged acetate silk and the methods of detecting it are given in Chap- 
ter XIX, on the Saponification Method of Dyeing Acetate Silk. 


Desizing Acetate Silk 


Method No. 1: Removal of Size. Steep in an aqueous bath 
containing 50 grams. per liter of diastofor at 60° C. (140° F.) 
for about 30 minutes. (Possibly better than Method No. 3.) 

Method No. 2: Removal of Size. Work for 30 to 45 minutes in 
a bath containing 4 to 8 pounds of diastofor per 100 gallons, at 
60 to 71° C. (140 to 160° F.). The skeins may then be taken out 
and piled overnight. If a standing bath is used, replenish the bath 
with one-third to one-half of the original charge of diastofor. In 
case the bath is alkaline, correct this with acetic acid. = 

Method No. 3: Removal of Sige. Steep in an aqueous bath 
containing 35 grams of rapidase per liter at 80° C. (1 %aP sae 
15 minutes. 

Method No. 4: Removal of Size. Pad the goods in a hot aqueous 
solution of soluble oil. Roll them up and allow them to stand 
overnight. Then scour for at least an hour as in Method No. 6. 


THE METHODS USED 129 


Scouring Methods 


Method No. 5: Scouring Celanese Alone.2 Scour in a bath con- 
taining 1.25 to 1.5 grams of olive oil soap and either 1 cubic centi- 
meter of 20 per cent ammonia or 0.25 gram of sodium carbonate 
per liter at 75 to 80° C. (167 to 176° F.) for one-half to one hour. 
Rinse well in warm water and then in cold water. The sodium 
carbonate should not amount to more than 2 per cent, on the 
weight of the Celanese. 

Method No. 6: Scouring Celanese-Cotton Unions.2. Scour in an 
open tub at not over 80° C. (176° F.) for forty-five minutes to 
two hours in a bath containing 2.5 grams olive oil soap, 2.5 grams 
of 50 per cent Turkey-red oil, and 1 cubic centimeter of 20 per 
cent ammonia per liter. Then rinse well, as in Method No. 5, 
and it is ready for bleaching by Method No. 15. 

Method No. 7: Grimshaw’s! Modification of Method No. 6. 
Scour for an hour at about 80° C. (176° F.) in a bath containing 
2.5 grams per liter of olive oil soap and an equal amount of 
emulsified mineral oil, such as is used in raw silk scouring. 

Method No. 8: Scouring Lustron-Cotton Unions.2 The manu- 
facturers of Lustron recommend that it should be scoured with 
10 per cent of neutral olive oil. soap and 1 per cent of soda ash, 
on the weight of the goods, for about one-half hour at a maximum 
temperature of 80° C. (176° F.). 

Method No. 9: Scouring Lustron-Cotton-True Silk Unions. 
Unions containing Lustron and real silk in the gum may be boiled 
off in one or two changes of a three-quarters to one per cent 
neutral olive oil soap solution for about one hour at 93 to 96° C. 
(200 to 205° F.). 

At the present time there are a wide variety of scouring agents 
offered upon the market, many of which are excellent for certain 
special purposes on various textile materials. Many of these com- 
pounds are liquid combinations of soaps and solvents, and some 
contain free alkalies. Considering the nature of acetate silk, it is 
almost impossible to predict just what the action of some of these 
solvent scouring agents will be upon this fiber and therefore they 
should be used with extreme caution until complete tests, including 
dyeing and finishing, have been made upon the scoured fiber. 


130 ACETATE SESS 


Celascour 


Celascour was developed and placed upon the market by the 
manufacturers of Celanese particularly for use upon Celanese 
and materials containing it. This compound is probably similar 
in composition to some of those described above, i.e., a special 
mixture of soap or Turkey-red oil, with or without solvents, pos- 
sibly very slightly alkaline. It is used both as a pretreatment or 
scour before dyeing,? and in the S.R.A. dyebath, as an aid to 
leveling and penetration. In use, it is merely diluted with hot soft 
water and added to the soap scour or dye bath in the proportion of 
0.5 to 5.0 cubic centimeters per liter of bath. These baths are 
used in the same manner and at the same temperatures as those 
without the Celascour, as in Methods No. 5 and No. 6. After the 
operation, the acetate silk should be rinsed free of soap with soft 
water. 

Methods No. 10, No. 11, No. 12, No. 13, and No. 14 are given 
by various dye manufacturers as satisfactory for acetate silk, 
variety not stated. They are given here for comparison. 

Method No. 10: Scouring Acetate Silk Alone. Scour in a 25 
to 1 bath with 5 to 12 per cent of olive oil soap and 0.5 to 1 per 
cent of soda ash, on the weight of the material, at 60° C. (140° 
F.) for 30 minutes. Rinse hot and cold, if necessary, in water 
slightly acidified with acetic acid. 

Method No. 11: Scouring Acetate Silk Kmitted Fabrics. In 
scouring knitted fabrics which usually contain more or less oil, 
up to 1 gram of soda ash and 1 to 3 cubic centimeters per liter of 
a Turkey-red oil solvent hydrocarbon emulsion, such as are now 
common on the market, may be added to the above, Method No. 
10. (Some of the hexalin or tetralin scouring emulsions, such as 
Isomerpin, are widely used and should be excellent for this pur- 
pose. Celascour is also recommended. ) 

Method No. 12: Scouring Acetate Silk Alone. Scour at 45° C. 
(113° F.) with a solution containing 2 per cent of hard soap and 
4 per cent of ammonia, on the weight of the fabric, for 20 minutes. 
Rinse in two waters, sour in a bath containing 2.5 per cent of 30 
per cent hydrochloric acid, on the weight of the goods, and finally 
rinse. 


tobe vETHODS USED 131 


Method No. 13: Scouring Acetate Silk-Cotton Unions. Still 
another variation for unions is recommended. Scour at %5° C. 
(170° F.) in a bath containing 1 or 2 pounds of Monopole soap 
per 100 gallons of liquor. If the cotton is unbleached use a slightly 
higher temperature, 80 to 85° C. (175 to 185° F.), and rinse the 
goods as in Method No. 5. 

Method No. 14: Scouring Celanese. Scour in a solution con- 
taining one-half pound each of soap and ammonia, to each ten 
gallons of liquor, at 65° C. (150° F.) and rinse as in Method 
No. 5. 


Bleaching Acetate Silk 


Where pale or brilliant shades are to be dyed, it may be neces- 
sary in some cases to bleach the fabric containing acetate silk. 
The manufacturers of Celanese recommend that this should be 
done by Method No. 15. 

Method No. 15: Bleaching Celanese.2, Treat for one hour in a 
cold 0.25 Tw. sodium hypochlorite solution. This bath may be 
prepared as in Method No. 16 or from soda ash and chlorine, as 
for the regular cotton bleach. The bath may be either neutral or 
acidified slightly with acetic acid just before using. If the neutral 
bath is used, the goods may be acidified in a separate dilute acetic 
acid bath after leaving the bleach. The bleached Celanese should 
then receive an antichlor treatment, as given in Method No. 18. 

Method No. 16: Bleaching Lustron-Cotton-Viscose Unions.? 
The Lustron Company advise the use of hypochlorite on either 
Lustron-cotton or Lustron-cotton-viscose unions. Prepare a stock 
hypochlorite solution from 10 pounds calcium hypochlorite (bleach- 
ing powder) and 6 pounds soda ash in 50 gallons of water. Allow 
this to settle and use the clear liquid. 

Make up the bleach bath for use at 0.5 to 0.75° Tw. (1.0025 to 
1.004 sp. gr.) from the above clear liquor or from soda ash and 
chlorine direct, as mentioned in Method No. 15. After scouring 
as in Method No. 8, bleach in this bath at 25 to 30° C. (77 to 86° 
F.) for 1 hour. Rinse lightly and sour in a cold 0.5 per cent acetic 
acid solution for 15 or 20 minutes. Work until neutral, then 
neutralize in a bath containing 0.25 per cent of sodium bicarbonate 


132 ACETATE SIL 


for one hour. Hydroextract and dry without rinsing, or if the 
goods are to be dyed, rinse and proceed with the dyeing. A stand- 
ing bleach bath may be used to advantage. 

Method No. 17: Combination Scouring and Bleaching. A 
shorter combination method of scouring and bleaching in a single 
bath at one operation has been suggested. In this process, about 
9.5 cubic centimeters of sodium hypochlorite is added to each liter 
of scouring liquor, so that the scouring and bleaching proceed 
simultaneously. In using this method, particular care must be 
taken to be absolutely sure that the hypochlorite solution is free 
of calcium salts, as in the presence of soap, these are sure to cause 
spots on the material during dyeing. No matter what method of 
hypochlorite bleaching is used, the bleach bath should not contain 
any calcium salts. 


Antichlor Treatment 


In bleaching any variety of rayon, and especially acetate silk, 
with hypochlorite, it is particularly important that every trace of 
chlorine be removed from the bleached fiber, by the use of suit- 
able antichlors and thorough rinsing. 

Method No. 18: Antichlor Treatment for Celanese.? The 
Celanese manufacturers recommend that after the hypochlorite 
bleach, as in Method No. 15, the Celanese should have an anti- 
chlor treatment for 15 minutes in a cold bath containing 0.5 to 
1 gram per liter of sodium bisulfite. This should be followed by a 
thorough rinsing. 


Peroxide Bleaching 


Besides the above bleaching methods, the Lustron Company 
state that acetate silk may be bleached with peroxide and particu- 
larly recommend this method for unions containing true silk or 
wool. The hydrogen peroxide bleach on acetate silk, or unions 
containing it, is conducted in practically the same way as in bleach- 
ing wool, except that as usual in all wet processes on acetate silk, 
the peroxide concentration should be somewhat higher than that 
used for wool. : 

Method No. 19: Hydrogen Peroxide Bleach on Acetate Silk. 
The bath may be prepared with a concentrated solution of hydro- 


Poe METHODS USED 133 


gen peroxide or as follows: To prepare 100 gallons of bleach bath, 
add to each 97 gallons of cold water, 11 pounds of 56 per cent 
iron-free acetic acid. Sprinkle sodium peroxide slowly into this 
bath while stirring well to prevent undissolved peroxide from 
sinking to the bottom of the vat. When about half of the 
peroxide has been added, start heating the bath slowly to 38° C. 
(100° F.). Continue adding sodium peroxide while heating until 
the bath reacts neutral to litmus paper. Usually about 4 pounds of 
sodium peroxide are required to make up the neutral bleach bath. 
When the neutral point is reached, heat the bath to 49° C. (120° 
F.) and add 2 pounds of Monopole oil. Mix well and enter the 
goods as quickly as possible at 49° C., maintaining this temperature 
until the proper bleach is obtained. In the case of Celanese, the 
temperature should be held at 38° C. (100° F.). Where ammonia 
or sodium silicate is used in the peroxide bleach bath, only sufh- 
cient may be added to render the bath very faintly alkaline. After 
bleaching, rinse first in water at 38 to 49° C. (100 to 120° F.) and 
then in cold water. 

Method No. 20: Permanganate Bleach on Acetate Silk. The 
permanganate method of bleaching may also be used on acetate 
silk. » This bleach bath should be prepared with 1 pound of 
sodium or potassium permanganate per hundred gallons of hot 
water. The scoured acetate silk is worked cold in this bath for 
two or two and a half hours. As this bath becomes alkaline to 
litmus paper in use, acetic or sulfuric acid should be added to keep 
it very slightly on the acid side while the acetate silk is present. 
Usually about 100 to 200 cubic centimeters of concentrated sul- 
furic acid will be required for each pound of permanganate used. 

After the permanganate bleach, the brown manganese dioxide 
stains may be removed from the fibers by working them for from 
30 to 45 minutes in a cold bath containing 4 pounds of sodium 
bisulfite and up to 2 pounds of 66° Be. sulfuric acid in 100 gallons 
of water. If the acid is omitted, the clearing bath may be warmed 
somewhat to accelerate the reaction, or the amount of bisulfite 
may be doubled. When the skeins are white, they should be 
rinsed with fresh water until colorless. 

Feibelman® states that the rayons may be bleached with aktivin, 


134 ACETATE SILK 


which is the sodium salt of toluene-p-sulfochloroamide, without 
injury. Neutral solutions containing even 3 or 4 per cent of akti- 
vin at 60 to 70° C. (140 to 158° F.) do not affect either the luster 
or strength of rayon, although they bleach it only to a uniform 
cream color. Acid solutions of this strength give a full white. 
For example, 3 grams of aktivin are dissolved in a liter of water 
and 5 cubic centimeters of acetic or 50 per cent formic acid are 
added. The slightly turbid solution has a stronger bleaching action 
than aktivin itself and the rayon is not injured, even at high tem- 
peratures. Bleaching is complete in a half-hour and the material 
should then be treated with a bisulfite solution, before washing. 
While there is no apparent reason why this method should not be 
satisfactory on acetate silk, nothing definite has been given regard- 
ing its use on this fiber. | | 

It is interesting to note that Greenhalgh* reports instances of 
the “pinking” of acetate silk after bleaching when improperly 
washed, due to the presence of substances other than cellulose ace- 
tate, such as aniline, toluidine or xylidine, in the fiber. He states 
that the pink stains are the result of the oxidation of these or simi- 
lar compounds, that the color is analagous to that of Magenta, 
and that the stain may be removed by soaping or by a further light 
bleach. 

Bluing or Tinting Acetate Silk White 

In case the acetate silk is to be used undyed and it is desired to 
improve the natural color without an actual bleaching operation, 
the fiber may be blued by tinting it in a bath containing a violet or 
blue dye of a reddish shade. The dyes most frequently used for 
this purpose are the Methyl Violets and Indanthrene Violets or 
Blues, although certain other dyes could be used for the purpose. 
In case the Indanthrene dyes are used, the prepared thick dye 
paste is simply diluted with water and added directly to the “blu- 
ing” bath without reduction. 


Degumming True Silk in Acetate Sik Combinations 
Before dyeing combinations of acetate silk with true silk it is 
frequently necessary to boil-off the true silk as well as desize the 
acetate silk. In the case of Lustron, this boil-off may take place 


Slob eMETHODS USED 135 


in the usual boiling neutral soap degumming bath without injury 
to the acetate silk. In the case of Celanese there are several meth- 
ods of degumming without injury to the acetate silk, some of 
which are patented processes. It is obvious that in the case of 
Celanese or Rhodiaseta, temperatures of over 85° C. (185° F.) 
should not be used in degumming without special precautions, as 
mentioned in British Patents No. 206,113 and No. 246,879. Each 
of the following methods has its advantages for certain classes of 
work, 

Method No. 21: Degumming True Silk in the Presence of Cel- 
anese.” Impregnate the material with a strong aqueous solution 
of Turkey-red oil (50 per cent of fatty acids) containing 1 to 3 
per cent of sodium carbonate or its equivalent of sodium silicate, 
phosphate, or borate, at 75° C. (167° F.). Squeeze until the ma- 
terial contains only about its own weight of liquor and allow it to 
lay for 6 to 12 hours. Scour off twice at 75° C. in a solution con- 
taining 0.25 per cent of sodium carbonate and then rinse well 
with hot soft water 

Method No. 22: Degumming True Silk in the Presence of Cel- 
anese.2 Prepare an 80° C. (176° F.) steeping bath containing 
1 per cent of olive oil soap and enter the union, allowing it to re- 
main about 12 hours. Then add about another 1 per cent of the 
soap, on the weight of the bath, and about 0.25 gram per liter of 
sodium perborate, raising the temperature again to 80° C. Allow 
this to stand for several hours more, heating to 80° C. and adding 
the same amount of perborate again, if necessary, and work the 
goods carefully until the gum is removed. Then rinse free of soap. 

Method No. 23: Degumming True Silk in the Presence of Cel- 
anese.2 Prepare a 30 to 1 degumming bath containing 1 per cent 
of olive oil soap, on the weight of the bath. Add 1.5 per cent of 
sodium phenolate, on the weight of the goods, and treat the mater- 
ial at 80 to 85° C. (176 to 185° F.) for 2 hours. Rinse well with 
hot soft water. 

According to British Patent No. 206,113, July 11, and German 
Patent No. 395,829, June 17, 1923, to the Société Chimique des 
Usines du Rhone and the Société pour la Fabrication de la Soie 


*See Chapter XXV. 


136 | ACETATE SILK 


“Rhodiaseta,” it is not always necessary to degum true silk at 
temperatures below 85° C. when acetate silk is present. While 
both Rhodiaseta and Celanese are usually delustered on treatment 
with aqueous solutions above this temperature, these patents by the 
manufacturers of Rhodiaseta state that fabrics made from acetate 
silk either alone or in combination with raw true silk, may be de- 
gummed or/and desized without injury to the acetate silk by add- 
ing a neutral potassium salt, such as the chloride, sulfate, or dipo- 
tassium phosphate, etc., to the soap bath. It is claimed that the 
potassium salts, in the presence of salts of other metals, protect the 
acetate silk without retarding the foaming of the soap solution, and 
that the degumming and/or desizing may take place at the boil 
without detriment to the acetate silk in any way. A suitable de- 
gumming bath for use on an acetate silk—true silk unions may con- 
tain 0.5 to 2 per cent of neutral soap and 10 per cent of the neutral 
potassium salt, on the weight of the batli. The treatment is carried 
out at 90 to 100° C. (194 to 212° F.) until the gum of the true 
silk and the size of the acetate silk are removed, which usually re- 
quires 30 to 60 minutes. If the true silk contains much gum, a 
second treatment with a more dilute soap bath may be given. 
Very possibly some modification of this process could also be used 
in dyeing Rhodiaseta and Celanese at high temperatures. See Bri- 
tish Patent No. 246,879 which may also be used in degumming. 


References 


1A H. Grimshaw, Textile World 67, 579-81 (1925). ° 

2 American Cellulose and Chemical Company, “Notes On The Practical 
Dyeing of Celanese.” Celanese Dyeing Leaflet No. 2, 3rd Edition. 

®Tustron Company, “Recommendations for Finishing and Dyeing Fab- 
rics Containing Lustron Silk.” 

“E. Greenhalgh, Dyer and Calico Printer 55, 26 (1926). 

®R. Feibelman, Textilber. 7, 47 (1926). 

°R. V. Patchett, Textile Recorder 44, No. 522, 77-9 (1926). 

7W. Milne, American Dyestuff Reporter 15, 886 (1926). 


CHAPTER X 
ae DYES ON ACETATE SILK 


The Methods of Applying the Basic and Gallocyanine Dyes to 
Acetate Silk. The Use of “Assistants” and Patents Covering 
Same. The Ammonium Thiocyanate Method 


Earty in the development of acetate silk it was well known that 
it absorbed a few dyes substantively, but these were mainly basics. 
Some of these basic dyes possess a fastness to light and washing 
on certain acetate silk which is rather unexpected and entirely 
out of relation to their fastness on other fibers, even without a 
mordant. However, the affinity, and therefore the fastness prop- 
erties, of the various basic dyes, varies with the different brands 
of acetate silk. For instance, Lustron has the highest affinity for 
the basic dyes of any known commercial textile fiber, while Celan- 
ese does not have such a high affinity for them. The difference is 
so great that with certain dyes under suitable conditions, the 
Celanese, as well as all other fibers, may be left practically un- 
stained in a basic dye bath in the presence of Lustron. For ex- 
ample, if Lustron and Celanese are dyed together in the same bath 
with a basic dye, such as Rhodamine or Malachite Green, the Lus- 
tron will take on a very full shade while the Celanese will be dyed 
only a comparatively light shade. 

Very possibly the affinity of the acetate silks for the basic dyes is 
largely due to their sulfate and acetate groups and the difference 
in the affinity of the two varieties mentioned above may largely be 
due to the differences in their composition, although the finishing 
process may play some part in the difference. The fastness of the 
basic colors on acetate silk appears to follow closely the affinity of 
the basic dyestuff for the acetate silk and for this reason we may 
rightly expect the basic dyes on Lustron to have better fastness 
than on Celanese. Even the light fastness of many of the un- 
mordanted basic dyes is unexpectedly good on Lustron.? 


US7 


138 AGE DAT Eesti 


Dort,! the American authority on dyeing Celanese, points out 
that while some basic dyes really dye Celanese, others only stain 
it, and that only in a limited sense can Celanese be dyed with basic 
dyes. From the discussion in Chapter VIII on the application of 
basic dyes to acetate silk, this is to be expected, as is also the fact 
mentioned by Dort, that the fastness properties of the basic dyes 
on Celanese is entirely different from these properties on other 
fibers and frequently unsatisfactory. He cautions that the basic 
dyes should not be used on Celanese except under unusual cir- 
cumstances and with the most careful control and supervision. 

On account of the high affinity of the basic dyes for Lustron it iS 
possible to cross-dye basic colors on Lustron-cotton, silk, or wool 
unions, which will not withstand cross-dyeing on Celanese. With 
many basic dyes it is impossible to obtain heavy or even medium 
shades on Celanese without the assistance of special dyeing meth- 
ods or chemicals, such as those described under “Assistants.” 

The extreme difficulty in evenly dyeing the earliest acetate silk 
was undoubtedly due to the particular chemical character of the 
product in use at that time. Cellulose triacetate is extremely diffi- 
cult to wet-out, due to its high interfacial surface tension against 
all neutral or acid aqueous solutions, while the strongly alkaline 
solutions react chemically upon the acetate. Even the present prod- 
ucts are more difficult to wet-out than the ordinary textile fibers in 
the dye bath, and for this reason it is important that the acetate silk 
should be thoroughly wet-out in a separate scouring bath before it 
enters the dye bath. The still wet acetate silk should be entered 
into the basic or other dye bath before there is any possibility of its 
becoming dry in spots, or these spots will dye considerably lighter 
with most dyestuffs. 

All the usual precautions required in applying the basic dyes 
should be exercised in applying them to acetate silk. Where sev- 
eral dyes are to be used in the same dye bath, the usual care in 
selecting dyes which do not precipitate each other must be taken. 
Where such precipitation occurs, the dyes may be applied in sep- 
arate baths, instead of in one dye bath, and in some instances the 
fastness to water and washing may be greater than that of either 


Wie DASIC DYES 139 


component dye alone. Sodium hydroxide, and to a less extent 
sodium carbonate and soap, causes precipitation of certain basic 
dyes. These chemicals may also act upon the acetate silk and 
therefore should not be present in the basic dye bath. 

Where the dyestuff is difficult to dissolve, it should be made into 
a paste with dilute acetic acid or glycerol and a little alcohol. This 
paste may be diluted with warm water, dissolved in hot water, and 
finally added to the dye bath by filtering through a fine piece of 
cloth. Basic dyes which are dulled by metals should not be applied 
in iron, copper, or other metals which react with them. Low tem- 
peratures in the application of the basic dyes is desirable from the 
standpoint of the dyestuff as well as the acetate silk. 

Neutral sulfonated or monopole oil is frequently useful in. the 
basic dye bath as an aid in leveling and penetration. Glucose, 
acetin, and diastofor are also claimed to be of value in leveling the 
basic dyes on acetate silk. Both glucose and acetin may be used in 
the basic dye bath with zinc salts, which will be mentioned later. 
Silk boil-off liquor is absolutely useless in dyeing acetate silk. 
Possibly some of the new wetting-out agents, such as Celascour, 
Isomerpin, Nekol A, etc., may be useful either in the dye bath as an 
aid to penetration and leveling, or in previously wetting-out the 
acetate silk. In selecting these wetting-out assistants, care must be 
taken to avoid those containing solvents which may act upon the 
acetate. 

The presence of organic acids, such as acetic, formic, tartaric, 
and lactic acid, and certain neutral salts; such as sodium or am- 
monium sulfates, chlorides or acetates, in the basic dye bath tends 
to retard the absorption of dye by the acetate silk. Sodium chlor- 
ide and acetic acid are usually the most satisfactory for this pur- 
pose. This fact appears to support the statement of Greenhalgh? 
that the acetate silk is dyed only by the basic radicle of the basic 
dyes and not by the soluble compound of the basic dyestuff as a 
whole, the acid portion of the basic dyestuff molecule remaining 
in the dye liquor. The mineral acids should never be substituted 
for the organic acids in dyeing acetate silk. 

The usual bottom mordanting with tannin, Katanol, etc., widely 


140 ACETATE SILK 


used for basic dyes on cotton, is useless on acetate silk but some 
special compounds are useful in obtaining deeper and faster shades, 
and these will be mentioned later. Owing to the low specific gravity 
of acetate silk it does not sink much in water so that particular care 
must be taken to keep it submerged in the dye bath. 

The di- and triphenylmethane dyes have a good affinity for Lus- 
tron, the former being the most useful, as for instance Malachite 
Green, Magenta, and Chrome Violet. Increased methylation of 
the di- or triphenylmethane dye appears to decrease its fastness 
on acetate silk, possibly due to the increase in molecular weight. 
The thiazine dyes, such as Methylene Blue, are not usually so 
satisfactory ; but the oxazine dyes, which contain an atom of oxy- 
gen in place of the sulfur atom present in the thiazine dyes, are 
useful. Suitable oxamine dyes are Nile Blue, Capri Blue and New 
Methylene Blue. 

As is the case with all other classes of dyes on every fiber, the 
fastness of the individual members of the basic group varies con- 
siderably, not only with the individual dye itself, but also with the 
variety of acetate silk to which it is applied. For this reason it is 
difficult to give much definite information regarding the fastness 
to the various factors upon the different varieties of acetate silk. 
Acetate silk is more transparent to the ultraviolet light rays than 
any other textile fiber, and this characteristic may bring out another 
variation from the usual routine of light fastness tests. 

On account of the higher affinity of the basic dyes for Lustron, 
in applying these dyes to it, longer dye baths, more retarding agent, 
or/and lower dyeing temperatures must be used than in dyeing 
Celanese, in order to prevent unevenness. In many cases one per 
cent of the basic dye will give a deep shade on Lustron. The fol- 
lowing is a partial list of the many basic dyes which have been 
suggested for use upon acetate silk. It is compiled from a wide 
variety of sources and of course the affinity of the different prod- 
ucts varies considerably. The dyes starred are particularly fast 
to light on acetate silk although some of the others may be equally 
fast. 


Piel DYES 


Blue 


Thionine Blue 
*Tannocyanine B 
*Cresyl Blue 2RN, and 2BS, and 
2RS 
*Brilliant Cresyl Blue BB 
Rhoduline Blue 5B, 6B conc., GO, 
3GO 
Tannoturquoise BB 
Rhoduline Sky Blue BB and 3G 
Brilliant Rhoduline Blue R 
New Blue DA conc. 
*Turquoise Blue G and BB (very 
good) 
*Fast Blue RS 
*Capri Blue GON 
Medola Blue 
Victoria Blue 
Methylene Blues (not satisfactory 
on Celanese) 
Night Blues 
Nile Blues 
Indoine Blue 2RD 
Cotton Blue 2B 
New Methylene Blue F 
New Blue 13535 and R conc. 
Fast Navy Blue R 
Setocyanine 
Setoglaucine (very good) 
Indoine B and 3B 
Acronal Brilliant Blue (very good) 


Green 
*Green Yellow shade 32 
*Imperial Green GI 
*Malachite Green (very good) 
Ethyl Green 
*Brilliant Green crystals C.I. No. 
622 (very good) 
*Victoria Green WB 
*China Green crystals 
Methylene Green B, DG, G, GG, 
and O 
Solid Green crystals O 


Yellow 
*Rhoduline Yellow T and 6G 
*Janus Yellow R 
*Auramines 
Thioflavine T, TG, and TG extra 
Coriphosphine O and OX 


141 


Phosphines 

Auracine G 

Methylene Yellow 
Flavophosphines 

Acridine Yellow 2R and GR 


Orange 


Rhoduline Orange N and NO 
Chrysoidines (very good) 
Tannin Orange R powder 
Acridine Orange (very good) 


Red 


*Magenta (very good on Lustron) 

*Fuchsine 

*Rhodamines B, 3B, 6G extra and 
S (very good) 

*Rubine Crystals 

*Diamond Fuchsine 

*Acridine Red 3B 

*Pyronine G 

*Rosazeine B extra and 6G extra 

Rhoduline Red G 

Brilliant Rhoduline Red B 

*New Magenta Crystals 

Safranines 

Brilliant Safranine G conc, 

Induline Scarlet 


Violet 
*Methyl Violets 
Methylene Violet 
*Crystal Violets 
Ethyl Purple 6B 
Ultra Violet (a gallocyanine) 
*Brilliant Heliotrope 2R conc. 
*Rhoduline Heliotrope B and 3B 
*Methylene Heliotrope 
Brilliant Rhoduline Purple R 
Tannin Heliotrope 


Brown 


Vesuvine conc. 
Bismark Browns 


Grays and Blacks 
Prune Gray 
Methylene Gray B New 
Chrome Gray 
Artificial Silk Black 
Basic Black FCG and SB 


142 ACETATE SILK 


Some of the Janus dyes are also applicable to acetate silk, how- 
ever most of them give rather dull shades and require a compara- 
tively high temperature in the dye bath, which in the case of Celan- 
ese or Rhodiaseta may injure the luster. They are not particularly 
fast on Celanese. Chrome Blue is a chrome developing dye which 
is sometimes used with the basic dyes on acetate silk. Only small 
quantities of it may be used in the same dye bath with the basic 
dyes. As it is affected by metals, copper should not be present. It 
has a very high affinity for acetate silk so that care must be used 
to avoid unevenness. 


Dyeing Methods for the Basic Dyes on Acetate Silk 


There are a number of methods for applying the basic dyes to 
acetate silk, but most of them vary only in the minor details. In 
order to give some idea as to the different variations offered, the 
following methods are given. It should be remembered that many 
neutral salts, as well as the organic acids, act as retards for the 
basic dyes on acetate silk. . 

The British Celanese Company formerly recommended that both 
the basic and gallocyanine dyes be applied to Celanese with acetic 
or formic acid and sodium chloride, using either soft or hard water. 
While the exhaustion of dyestuff is not nearly complete by this 
method, the brilliancy of shade obtained is often very desirable. 
The basic dyes are frequently used for topping other dyes on 
acetate silk, just as they are used on cotton and other fibers 
to secure brighter colors. More will be given in regards to 
topping later. A 25 or 30 to 1 dye bath is usually satisfactory for 
most basic dyes on Celanese. After dyeing the acetate silk should 
always be rinsed and given a light soaping at 45°. Ce (de eee: 
The following formulas are typical: 

Method No. 24: Basic and Gallocyanine Dyes on C elanese. 
Enter the material at 45° C. (113° F.) in a 25 to 30 to 1 dye bath 
containing about 1 cubic centimeter of acetic acid (100 per cent ) 
per liter, about 30 per cent of sodium chloride (on the weight of 
the goods) and the required amount of dyestuff. Dye up to two 
hours at 45 to 80° C. (113 to 176° F.), or until the desired shade 
is obtained. After dyeing always rinse the acetate silk well and 


Pb DA SLO DY ES 143 


soap it lightly at 45° C. to avoid crocking. With the above formula 
a saxe shade may be obtained with 0.3 per cent of Capri Blue GON 
and 0.006 per cent of Magenta Crystals; or a Deep Royal color 
with 1.5 per cent of Prune Pure. 

Method No. 25: Basic Dyes on Lustron. The basic dyes are 
applied to Lustron in approximately the same manner as in the 
above Method No. 24, except that a 30 or 40 to 1 dye bath, with 
more retarding agent, such as acetic acid should be used, and the 
Lustron entered cold. The temperature of the dye bath may then 
be increased gradually to 80° C. (176° F.). Lactic and tartaric 
acids have also been mentioned as retards for Lustron but do not 
appear to have any advantage over acetic acid. Of course it is 
easier to obtain level medium and full shades than tints. 

Method No. 26: Basic Dyes an Acetate Silk with Acetic Acid. 
Prepare the dye bath with 2 to 4 per cent of acetic acid, on the 
weight of the material to be dyed, and the required amount of 
dyestuff at 88° C. (100° F.). Enter the acetate silk at this tem- 
perature and work it for about 30 minutes. Then raise to 60 to 
71° C. (140 to 160° F.) and dye at this temperature until the 
bath is exhausted. 

Method No. 27: Basic Dyes on Acetate Silk with Ammonium 
Salis. Use at least a 20 to 1 or preferably a longer dye bath con- 
taining ammonium chloride, sulfate or acetate, and the dyestuff. 
Enter the acetate silk cold, raise the temperature to 60 or 70° C. 
(140 or 158° F.) in about a half hour and hold it there for the 
same length of time, when more ammonium salt, in solution, is 
gradually added to aid the exhaustion, until about 30 to 50 per 
cent of the salt is present in the dye bath. Also see Method No. 41 
on the application of acid and mordant dyes with ammonium salts. 

Method No. 28: Basic Dyes on Acetate Silk with Magnesium 
Chloride. Enter the acetate silk cold into the dye bath containing 
1 or 2 per cent of acetic acid and 5 to 20 grams per liter of either 
magnesium or sodium chloride. Heat the dye bath gradually so 
that in about an hour a temperature of about 80 or 85° C. (176 or 
185° F.) is reached. Finish in water containing acetic, formic, or 
tartaric acid. A “‘scroop” finish may be obtained by adding a 
little olive oil emulsion to the acid finishing bath. 


144 AGETATE Sich 


Dyeing Acetate Silk with Various “Assistants” 


The fact that tannin and other mordanting agents, such as are 
used upon cotton in applying the basic dyes, are useless upon 
acetate silk was mentioned before. However certain other com- 
pounds, which are possibly best described as ‘‘assistants,” are 
useful in obtaining deeper shades and increasing the fastness to 
water, soaping, etc. Most of these assistants are salts, usually 
inorganic, although some organic compounds have also been 
patented for this purpose, as will be seen from the patents which 
follow later. 

The assistants are compounds which form double salts with the 
basic dyes. These double salts appear to be less soluble in water 
and more soluble in acetate silk than the basic dyestuff alone, with 
the result, as mentioned in Chapter VIII, that much deeper and 
faster shades are obtained. Pokorny? mentions that acetate silk 
which has been treated with a 6 per cent aqueous solution of 
resorcinol also gives deeper shades with the basic dyes than the 
normal fiber, and states that the action is a partial deacetylation of 
the fiber. While the process is rather expensive it may have some 
use for printed color effects. 


Celloxan 

Celloxan is a viscous liquid produced by Bayer and Company 
for use in applying the basic dyes to acetate silk and contains a 
large proportion of zinc nitrate.* Its application is very simple as 
shown by Method No. 29 which covers this process. Celloxan 
does not impair the luster, handle, or strength of the acetate silk 
and has no saponifying action. The resulting shades are stated 
to have a good fastness to washing. The Katanol or tannin after- 
treatments given in Methods No. 32 and No. 33 are claimed to 
increase the fastness of basic dyes, when applied either with or 
without Celloxan. 

Method No. 29: Application of Basic Dyes with Celloxan. Dis- 
solve the dyestuff in the usual manner and add it to the 20 to 1 
dye bath at about 70° C. (158° F.). Then add the proper quantity 
of Celloxan as given in Table XXIII. Enter the acetate silk and 
dye for about three-quarters of an hour at 70° C. After dyeing, 
hydroextract, rinse well, brighten in a bath with 1 per cent of 


*See British Patent No. 216,838, which possibly covers this process. 


ioe bASLO DYES 145 


acetic acid at 40° C. (104° F.), and dry at 30 to 40° C. (86 to 104° 
F.). When a standing bath is used, it is usually necessary to add 
only about half the original quantity of dye and Celloxan to re- 
plenish the bath. In the case of the dyes marked *, it is advisable 
to add the Celloxan in two portions, adding one-half of the quan- 
tity at the start, and after about fifteen minutes add the remainder. 
The dyes marked j are particularly fast to light. 


TABLE XXIII 
AMOUNT OF CELLOXAN TO BE USED IN APPLYING THE VARIOUS DvEs 


Cubic Centimeters of Celloxan 
per Liter of Dye Bath for a 


Name of Dyestuff 2% Dyeing 
Yellow 
Auracine G 10. 
tAuramine O | 20. 
Auramine G 20. 
Coriphosphine O and OX 1S. 
tRhoduline Yellow T and 6G se 
Orange 
Chrysodine G extra and R extra iS) 
Rhoduline Orange N and NO i 15. 
Re ‘ 
*Rhodamine 3B id: 
*+Rhodamine 6G extra 6. 
Rhoduline Red B Wig 
* Rhoduline Red G Paiva eh ts) 
*tNew Fuchsine 10 tos 5) 
*+Diamond Fuchsine 10. to 15. 
Safranine FF extra 10. 
Brown 
Bismark Brown FR extra 20. 
’ Violet 
+Brilliant Rhoduline Violet R Olas 
*+Crystal Violet P 10. 
*+Methyl Violet 1B, 2B and 4B 4, 
*+Methyl Violet 5B and 6B Se 
*+Methyl Violet 1R and 4R 4, 
**+Rhoduline Heliotrope B and 3R 10. 
Blue 
Methylene Blue B, BB, and RR 15. 
New Methylene Blue F Loy 
**Rhoduline Blue 5B Be 
tRhoduline Blue 6G conc. 15; 
Rhoduline Blue GO and 3GO Rae 
Rhoduline Sky Blue BB and 3G ee 
TtTurquoise Blue BB and G Le 
Brilliant Rhoduline Blue R 15. 
Green 
tMethylene Green B (5; 
Brilliant Green Crystals 1D: 
tChina Green Crystals La 


tNew Green GI 15% 


146 ACETATE SILK 


Acetane 


Acetane is a product of Weiler-ter Meer resembling Celloxan, 
used for the same purpose and in about the same manner. By add- 
ing acetane to the basic dye bath, deep shades are possible on acetate 
silks with certain basic dyes which otherwise are only applicable for 
light shades. Acetane has no detrimental effect upon the valuable 
properties of the acetate silk and in many instances deep shades 
may be obtained with only 1 or 2 per cent of dyestuff. It can be 
applied by Method No. 29, but by using the amount of Acetane 
shown in Table XXIV. The products starred are particularly 
fast to light. 


TABLE XXIV 
WEIGHT OF ACETANE TO BE USED xe THE VARIOUS DyEs ON ACETATE 
ILK 
Weight of Acetane in Ounces 
per Ten Gallons of Dye Bath 
Name of Dye 
Auramine 16; 
* Auramine O and II <p 
Phosphine GG, GR and RE 24; 
Vitoline Pure Yellow 6G 24. 
Vitoline Yellow 5G, G, R and 2R 24. 
Vitoline Orange N 24. 
Chrysodine GG, G, 2GR and R 24. 
* Carthamine B, G and 6G 24. 
* Cerise B and G 24. 
* Magenta 24. 
Safranine G and N ° 6.4 
* Crystal Violet 8. 
* Methyl Violet 10B, 5B, 2B, B, R, 3Rand5R 16. 
Red Violet 24. 
* Basilene Brilliant Blue 5B 24. 
Methylene Blue B, BG and M 24. 
Navy Blue B, R and 2R 24. 
Victoria Blue B and RBN 24. 
Sapphire Blue G, R and 3R 24. 
* Basilene Blue AZG and AZR 24. 
* Malachite Green 24. 
* China Green 4GN, G, 3G, G 2N and B 24. 
Methyl Green 24. 
* Brilliant Green 24. 
Bismark Brown 2G 32. 
Phenylene Brown 2G S45 


New Grey : 
Basilene Black AZ 24. 


* 


Pre BASIG DYES 147 


Bensancon* states that acetate silk is readily dyed with basic 
dyes after treatment with Kuhlmann’s Acetonol N. Before dye- 
ing, the fiber is immersed in an Acetonol N bath at 30 or 40° C. 
(86 or 104° F.) for 20 minutes. After centrifuging and washing, 
it is dyed with any of the common basic dyes without loss of lus- 
ter or other desirable properties. 


Topping with Basic Dyes 


The “mordanting” action of the acid dyestuffs for the basic dyes 
on various fibers is well known and widely used but it is not com- 
monly known that this process may also be used to advantage 
on acetate silk. Even though the acid dye itself has only a slight 
affinity for the acetate silk, giving merely tints when used alone, it 
has a decided’ effect upon the depth of the shade obtainable with 
the basic dyes, as well as upon the exhaustion and fastness of 
the resulting color. In this manner it is also possible to apply 
basic dyestuffs which have no direct affinity for the acetate silk. 
This will be discussed more fully under the acid dyes. Also see 
the Setacyl and Setacyl Brilliant dyes, under Dyeing by Precipi- 
tation, Chapter XI. | 


Patents on Dyeing “Assistants” 


One of the first patents covering the use of salts in the basic 
dye bath was that of R. Clavel, British Patent No. 176,535, Decem- 
ber 4, 1920. United States Patent No. 1,378,443, May 17, 1921, 
covers the same process. He states that the dye bath may contain 
one or more chlorides and an acid, with or without a protective col- 
loid. Suitable chlorides are given as those of ammonium, potassium, 
sodium, barium, magnesium, zinc or tin (ous). Formic or acetic 
are suitable acids and the protective colloid may be gelatin, albumin, 
silk boil-off liquor, tannates, soaps, sulfonated fatty acids, etc. 
The dyeing is preferably effected in a foam bath as described 
in British Patents No. 102,310 and No. 103,638 which cover real 
silk dyeing. British Patents No. 187,964 (United States Patent 
No. 1,549,906), No. 199,754, and No. 204,179 cover similar 
processes. In a later patent, British Patent No. 182,830 (1922), 
Clavel states that magnesium chloride and stannous chloride in 


148 ACETATE SILK 


the dye bath increases the affinity of the basic dyes for acetate 
silk. Also see British Patent No. 182,844; German Patent No. 
355,533; and United States Patent No. 1,448,482, which cover the 
use of inorganic salts in the dye bath. 

F. Bayer and Company obtained one of the first patents cover- 
ing the use of organic compounds as assistants in the basic dye 
bath. Their British Patent No. 215,373, May 1, 1923, and United 
States Patent No. 1,517,581, December 2, 1924 (to P. Rabe), 
covers the use of pyridine and its homologues, such as methyl- or 
amino-pyridine in dye baths in connection with basic dyes. For 
example, a kilogram of Diamond Fuchsine (Magenta or Fuchsine) 
is dissolved in 1000 liters of water, to which 10 kilograms of pyri- 
dine are added. The wet-out material is placed in the dye bath 
and the dyeing carried on at about 60 to 70° C. (140 to 1677 - Ee) 
for a half hour, after which any pyridine adhering to the fibers is 
removed by washing in dilute acetic or formic acid. 

According to British Patent No. 215,783, May 9, 1924, to 
Carpmael and Ransford (Bayer and Company), acetate silk may 
be dyed in the presence of hydrogenated pyridine (piperidine), 
Or a urea, or a derivative thereof, except the salts. For instance, 
guanidine, creatinine, or other aliphatic bases, or a compound of 
which these bases form a part, may be used instead of pyridine 
itself as described in British Patent No. 215,373 and United 
States Patent No. 1,517,581. For example, 5 kilograms of ace- 
tate silk may be dyed in a 100 liter dye bath containing 100 grams 
of Magenta and 1000 grams of piperidine or guanidine, at 60°C. 
(140° F.) for 30 or 45 minutes. The dyed material should be 
rinsed and acidified in the cold. The above patents were super- 
seded by British Patent No. 216,838. 

British Patent No. 216,838, May 28, 1923, to F. Bayer and 
Company possibly covers products such as Celloxan and Acetane. 
This patent states that in dyeing acetate silk (or other cellulose 
esters or their transformation products), a salt of an oxyacid 
of nitrogen or chlorine may be added to the dye bath in order to 
obtain deeper shades without using protective colloids. For in- 
stance, aniline nitrate may be used with Chrysoidine G; or sodium 
nitrate with Crystal Violet P. Nitrates of ammonia, sodium, 
magnesium, calcium and zinc, or of organic bases such as mon- 


eee AOL YES 149 


omethylaniline, guanidine, pyridine, or piperidine may be used, 
as may also their chlorates. Methylene Blue, Rhoduline Red B, 
Safranine, Auramine, and Bismark Brown are given as suitable 
dyes for application by this process. 

As an example, this patent states that 1 part of Chrysoidine G 
may be dissolved in 1000 parts of water and 5 parts of aniline 
nitrate added. The dye bath should be in the proportion of about 
®0 to 1, at a temperature of 70° C. (158° F.), and the material 
dyed for at least one-half hour. Other inorganic and organic 
nitrates are mentioned, and in another example it is suggested to 
use 5 parts of sodium nitrate in place of the aniline nitrate, with 
the same quantity of dyestuff and water. A chlorate may be 
substituted for the nitrate. 

R. Metzger in United States Patent No. 1,532,427, April 7, 
1925, and J. Y. Johnson in British Patent No. 240,514, June 2, 
1924 (Badische Company ), states that the glyceryl acetate or other 
organic acid esters are frequently added to cellulose esters during 
manufacture in order to render the artificial silk more susceptible 
to dyeing.” Such compounds have also been used in the dye bath 
but are liable to attack or even destroy the fiber. In order to 
avoid this deleterious action and at the same time increase the 
affinity of the acetate silk for dyestuffs, he suggests treating the 
fiber with a solution of an ester of a mineral oxygen acid, espe- 
cially salts of acid esters of a mineral oxygen acid, such as acid 
esters of sulfuric, phosphoric, or boric acid. The treatment with 
these esters or ester salts may be given in a bath previous to dyeing 
or the compound may be added to the dye bath, treating at either 
ordinary temperature for a considerable time or a higher tem- 
perature for a shorter time. 

For example: 10 kilograms of acetate silk may be treated for 
about ten minutes at 50 to 60° C. (122 to 140° F.) with 300 liters 
of a 50 per cent by weight, solution of potassium ethyl sulfate 
containing a little acetic acid. The treated acetate silk is hydro- 
extracted, stretched, and dyed without rinsing at 40 to 70° C. 
(104 to 158° F.) with one per cent of Diamond Green B in a bath 
slightly acidulated with acetic acid. 


"See German Patent No. 228,867. 


150 ACETATE ‘SILK 


According to the same patent, 10 kilograms of acetate silk may 
be entered into a 200 liter dye bath at 40° C. (104° F.) containing 
100 grams of Auramine ITI, a little acetic acid and 6 kilograms of 
a 30 per cent aqueous solution of sodium dicresyl phosphate. 

In the same manner, 1 kilogram of acetate silk may be worked 
for 10 minutes in 30 liters of a 5 or 6 per cent aqueous solution of 
sodium dicresyl phosphate, either at ordinary or an elevated tem- 
perature. It is then wrung out, stretched and dyed with 0.8 per 
cent of Methyl Violet 2B Extra at from 40 to 70° C. (104 to 
158° F.), with or without the addition of purified waste sulfite 
cellulose liquor. Or the pretreated fiber may be dyed with 1 per 
cent of Azoflavine RS in a dye bath slightly acidified with acetic 
acid, in place of the Methyl Violet. * 

If preferred, 1 kilogram of the acetate silk may be treated at 
40 to 50° C. (104 to 122° F.) with 30 liters of a 10 per cent 
solution of sodium dicresyl phosphate, wrung out and dyed at 40° 
C. (104° F.) with 10 per cent of Indanthrene Blue GCD paste 
(C. I. No. 1113), with or without the addition of a protective 
colloid, in a dye bath of which each liter contains three cubic centi- 
meters of 40° Be. sodium hydroxide solution, 2 grams of sodium 
hydrosulfite powder and 10 grams of Glauber’s salt. Also see 
British Patent No. 244,143. 

According to Haerry® very good results along the same line as 
that obtained by means of Celloxan and Acetane, that is a better 
exhaustion of the dye bath, and an increased fastness with basic 
dyes, may be obtained by using certain soluble zinc salts, such as 
zinc chloride, nitrate, or preferably the acetate, in the basic dye 
bath. He compares the action of these salts to the “salting out” 
action of sodium chloride or sulfate in the application of the 
direct dyes to cotton; however, he may be in error on this theory. 
In some cases the zinc salt precipitates the basic dyestuff directly, 
in which case considerable care must be exercised in its use and 
the presence of acetic acid in the dye bath may be advantageous. 
The zinc salt should be added only in solution. He states that the 
action of the zinc salt is particularly noticeable in the case of basic 
dyes which do not exhaust well or give deep shades on acetate silk 
alone, such as Magenta, Victoria Blue, Phosphine, Auramine, etc., 
in which case the zinc may double the depth of shade with a con- 


(ate BASIC DYES | 151 


sequent saving where a standing dye bath is not used. Further- 
more it will shorten the time of dyeing and allow lower tempera- 
tures to be used in the dye bath, both of which are an advantage 
when working with acetate silk. It also increases the fastness te 
rubbing, but in case this is not sufficient the dyed acetate silk may 
be rinsed for 15 minutes at 80° C. (176° F.) in water containing 
about 2 per cent of acetic acid. 

Method No. 30: Applying the Basic Dyes with Zinc Salts. 
For light shades, prepare the 15 or 20 to 1 dye bath with about 
half the required amount of dyestuff and a little acetic acid. For 
dark shades the dye may all be added at the start. Enter the 
skeins luke warm and after working a few times remove them and 
add the remainder of the dyestuff in solution. Immerse the skeins 
again and slowly raise the temperature to 50° C. (122° F.). 
Continue working at this temperature until very little more color 
is going on the fiber and then start adding the zinc salt (in solu- 
tion) in small portions, gradually raising the temperature to 55 
or 66° C. (130 to 150° F.). The amount of the zinc salt varies 
with the particular dyestuff used and is best determined by ex- 
periment. It has been stated that the presence of acetin or glu- 
cose in the dye bath aids in leveling. 

It is interesting to note that British Patent No. 247,694 to E. 
Knecht and F. Muller covers the use of water soluble compounds 
of magnesium and zinc in the application of the direct cotton dyes 
to cotton, in order to obtain colors which are faster to washing. 


Dyeing Acetate Silk with Ammonium Thiocyanate 


Among other special methods of applying the basic, as well 
as other dyes to acetate silk, the British Cellulose and Chemical 
Company in British Patent No. 158,340, October 31, 1919; and 
Briggs and Palmer in United States Patent No. 1,398,357 Novem- 
ber 29, 1922, suggest treating the acetate silk, either before or 
during the dyeing, with ammonium thiocyanate in solution in 
order to increase its affinity for basic, acid, direct, vat and other 
dyestuffs. Sodium, potassium or calcium thiocyanate may be sub- 
stituted for the ammonium salt.° Methyl Violet, Coomassie Acid 


© Also see the use of thiocyanates under Mordanting. 


152 ACETATE SILK 


Blue R, and Dianol Fast Red K are given as examples of the 
many products applicable by this method. Five to twenty-five 
per cent solutions of the salt, at various temperatures, are applied 
for from two minutes to an hour or more. 

These thiocyanates have a certain action on acetate silk which 
renders it more capable of absorbing and retaining basic, acid, 
direct, vat, and other dyes which alone have little or no affinity for 
acetate silk. However the results are not entirely satisfactory and 
the process has not come into general use. Too much thiocyanate 
will dull the luster of Celanese and possibly also of Lustron. Hall 
states that a microscopic examination of acetate silk treated with 
ammonium thiocyanate shows the surface to be crinkled. Wilson 
points out that the dyeing properties of viscose rayon are much 
increased when the surface is crinkled. Hanney suggests that 
thiocyanate has quite an action on cellulose itself at certain con- 
centrations, and it is possible that the action on acetate silk may in 
some respects resemble the mercerization of cotton. 

Method No. 31: Dyeing Acetate Silk With the Aid of Ammo- 
nium Thiocyanate. For example, the acetate silk may be treated 
for 15 minutes in a 25 per cent aqueous solution of ammonium 
thiocyanate, then washed in cold water and finally dyed in a 
bath containing 5 grams of Dianol Fast Red K per liter of water 
at 20° C. (68° F.). Many acid and direct dyes require only a 
15 per cent solution of the thiocyanate. Another method is to 
dye the acetate silk for 15 minutes at 40 to 60° C. (104 to 140° F.) 
in a dye bath containing 1 kilogram of Naphthol Blueblack, 30 
grams of Orange G and 24 kilograms of ammonium thiocyanate, 
per hundred liters. Vat dyes may be applied in a dye bath pre- 
pared with sodium hydroxide and hydrosulfite. In the case of 
Durindone Red B, the prepared vat is diluted with an equal vol- 
ume of 3 per cent thiocyanate solution, and the acetate silk dyed 
at 20° C. (68° F.). Also see British Patent No. 244,143. 


Basic Dyes on Saponified Acetate Silk* 


Of course the basic dyes may be applied to saponified acetate 
silk in the same manner as they are applied to cotton or the older 


4See Chapter XIX. 


ie bASLC DY HS 153 


rayons. ‘Their affinity for the saponified fiber will vary in each 
case with the particular fiber to be dyed and the individual dye- 
stuff used. In many cases where the basic dyes are to be used on 
the saponified fiber, it may be desirable to mordant the saponified 
acetate silk. This may be done in the same manner as given for 
mordanting cotton or the older rayons. British Patent No. 224,218 
mentions that sulfurized phenols are applicable to saponified ace- 
tate silk as a mordant for the application of basic dyes. 


Increasing the Fastness of Basic Colors on Acetate Silk 


Method No. 32. Katanol After-Treatment to.Increase Water 
Fastness of Basic Colors on Acetate Silk. After dyeing and rins- 
ing the acetate silk, but before drying it, enter it in a cold bath 
containing 3 to 6 per cent of Katanol and work it for 20 to 30 
minutes. Rinse again and dry as usual. 

Method No. 33: Tannin Treatment for Increased Fastness to 
Washing. In the same manner the fastness may be increased to 
washing by means of tannin and antimony, but with a dulling of 
‘the shade. The dyed and rinsed acetate silk is treated with 2 to 
4 per cent of tannic acid for about an hour at 38° C. (100° F.) 
and then without rinsing, in a cold bath containing 1 to 2 per 
cent of tartar emetic for about 30 minutes. In many cases the 
fastness may be rendered satisfactorily by simply treating the 
dyed acetate silk in a single bath containing 0.5 per cent of tannic 
acid. 

Method No. 34: Copper Sulfate Treatment of Basic Dyes to 
Increase the Light Fastness. ‘The fastness to light of the basic 
dyes on acetate silk may in some cases be increased by rinsing the 
dyed acetate silk and then treating it in a bath containing 2 per 
cent of copper sulfate and a little acetic acid at 55 to 60° C. 
(130 to 140° F.) for 15 minutes. The shade is more or less dulled 
by this treatment. Also see British Patent No. 243,841, on a 
method of increasing the light fastness of colors. 

In connection with the fastness of colors to light, it is interest- 
ing to note that Underwood reports that the light fugitive colors 
are protected from this fading action to some exent by treating 
the dyed material with a dilute solution of phenol or resorcinol. 


154 AGETATE SIE 


The Gallocyanine Dyes on Acetate Silk 


The Gallocyanine dyes are of the basic mordant class and Clavel 
discovered that many of them could be applied directly to acetate 
silk. The Gallocyanine dyes have an affinity for acetate silk both 
by virtue of their basic function, due to the alkylamine groups, 
and the phenolic function of their gallic acid groups. They give 
violets, blues, and grays on acetate silk, many of which have good 
fastness to light and washing. Prune Pure,° also known as Violet 
PDH, is particularly fast and gives shades from lavender to rich 
navy blue. Modern Violet, Coreine RR, Gallamine Blue and 
Gallo Sky Blue are also useful.’ Celestine Blue B gives good 
results but is not very level dyeing. 

Many of these dyes are sensitive to metals and therefore copper 
dyeing vessels must not be used for their application unless am- 
monium thiocyanate is added to the dye bath. The dyestuff should 
be dissolved cold and the scoured wet fiber entered into the cold 
dye bath to prevent unevenness. Most of these dyes give brilliant 
shades but do not exhaust very well. The goods should be soaped 
after dyeing, and the colors may be fixed and developed by an 
after-treatment with bichromate and acetic acid as in Method 
No. 36. The Gallocyanine derivatives, such as Brilliant Alizarine 
Blue G, also dye acetate silk, provided they do not contain more 
than one sulfonic acid group. The addition of chromium acetate 
to the dye bath when applying the gallocyanine dyes will improve 
the fastness of some of them to washing. Methods No. 24 and 
25 cover the application of both basic and gallocyanine dyes. They 
may also be applied by Method No. 35. | 

Method No. 35: Gallocyanine Dyes on Acetate Silk. Modern 
Violet, Gallocyanine, and Modern Heliotrope may be applied to 
acetate silk by entering the material into a cold dye bath and gradu- 
ally raising the temperature. After dyeing, the shades should be 
soaped, and the ultimate shade developed and fixed by after-treat- 
ment in a chrome bath as in Method No. 36. Possibly certain other 
dyes of this class are also applicable by this method. 

Method No. 36: Developing and Fixing the Gallocyanine Dyes 
on Acetate Silk. Enter the dyed and rinsed acetate silk into a 
fixing bath containing 1 to 2 per cent of bichromate and the same 


Pree bAolG DYES 155 


amount of 40 per cent acetic acid. After working for some time, 
rinse the acetate silk well and dry at a low temperature. 

It may also be well to note here that many of the free color bases 
of the basic colors, which are comparatively insoluble in water, 
may be applied to acetate in the form of aqueous suspensions by 
the dispersol method of application, which is discussed in Chapters 
mei AXIT and XXIII. 


References 


*R. G. Dort, American Dyestuff Reporter 15, 258-66 (1926). 

2 E. Greenhalgh, Dyer and Calico Printer 55, 106 (1926). 

$j. Pokorny, Rev. gen. mat. color, 29, 224 (1926). 

‘J. Besancon, Kunstseide 7, 120-1 (1925). 

See. faerry, “Artificial Silks.” 

*W. E. Sanderson, J. Soc. Dyers and Colourists 38, 162-5 (1922). 
‘J. F. Briggs, J. Soc. Dyers and Colourists 37, 287-96 (1921). 
®H. W. Underwood, Jr., Proc. Nat. Acad. Sci. 11, 78-80 (1925). 


CHAP Di ha ace 
DYEING BY PRECIPITATION 


Applying the Basic and Other Dyes by Precipitation Methods and 
the Patents Covering This Process. The Setacyl and Setacyl 
Brilliant Dyes 


The Setacyl and Setacyl Brilliant Dyes 


Wuite the Setacyl dyes of the Geigy Company are very prob- 
ably not all members of the basic group, at least some of them 
appear to belong to this classification; and their application by 
means of Setacyl Salt A, while possibly best described as a precip- 
itation process, appears to resemble the application of the basic 
dyes by means of “assistants.” It was previously stated that many 
organic compounds, such as dyestuffs, have a greater affinity for 
acetate silk when in a relatively coarse dispersion in the dye bath, 
as in the dispersol method of dyeing, than when in a higher state 
of molecular dispersion (or solution) such as in the ordinary dye 
bath. Very probably the increased affinity of the Setacyl dyes for 
acetate silk in the presence of Setacyl Salt A is due to the de- 
creased solubility of the compound formed in water and the in- 
creased affinity for, or solubility of the new compound in, acetate 
silk. 

The Setacyl and Setacyl Brilliant dyes are both entirely sepa- 
rate and distinct from the Setacyl Direct dyes which will be dis- 
cussed with the acid dyes. Very probably there is considerable 
difference in the composition of the brands of dyes now under 
discussion. Probably the Setacyl dyes are a group of specially — 
selected basic, acid, and mordant dyes, while the Setacyl Brilliant 
dyes appear to be new products, regarding the composition of 
which very little appears to be known at present. The two groups 
are applied with Setacyl Salt A in an entirely different manner 
from that used for the Setacyl Direct dyes. 


* See Chapter XII? 
156 


Darin BY PRECIPITATION 157 


It is possible, for instance, that Setacyl Yellow AO may cor- 
respond to Auramine O; Setacyl Green M may be Methylene 
Green (C. I. No. 924), which is one of the fastest basic green 
dyes ; Setoglaucine may correspond to Setacyl Turquoise Blue S; 
and Setacyl Sky Blue S, to Setocyanine; etc. However the fact 
that some of these dyes are members of the older basic class does 
not necessarily indicate that they do not have different and valu- 
able new properties when applied to acetate silk by Method No. 
3%. The depth of shade obtained by this method indicates that at 
least the exhaustion is entirely different from that of the basic 
dyes alone, and from the discussion in Chapter VIII, we would 
expect them to have better fastness properties to water and wash- 
ing also. 

The Setacyl Brilliant dyes appear to be new dyestuffs and as 
yet nothing definite has been learned regarding their constitution. 
Judging from the fluorescent properties of the resulting colors, 
they appear to be related to fluorescein. The beautiful yellowish- 
pink shade of Setacyl Brilliant Pink G suggests a relationship to 
Eosine (C. I. No. 768). While Setacyl Brilliant Scarlet B, G, and 
R are fluorescent, they do not possess this property to the extent 
of the pink. 

G. L. Hugel obtained French Patent No. 589,745, February 
9, 1924, upon a process for the manufacture of some fluorescent 
diphenylmethane dyes suitable for use on both acetate and true 
silks, but whether these products are related in any way to the 
Setacyl Brilliant dyes is a question. 

In this process, diphenylmethane dyestuffs are condensed with 
phenylmethylpyrazolone, B-naphthol, or nitromethane in aqueous 
solution and the leuco-products subsequently oxidized. For ex- 
ample, a dyestuff which gives fluorescent shades fast to light upon 
the above fibers is obtained by condensing. Thiopyronine with 
phenylmethylpyrazolone in an aqueous solution of sodium hy- 
droxide. Under similar conditions a golden yellow dyestuff with 
a green fluorescence, and red fluorescent dyestuffs, suitable for 
acetate silk and true silk, are obtained from Acridine Orange and 
phenylmethylpyrazolone, and from Thiopyronine and nitrome- 
thane, respectively. 


158 ACETATE SIZES 


The Setacyl and Setacyl Brilliant dyes are applied to acetate 
silk at low temperatures from a bath only slightly acid with ace- 
tic acid, and therefore the valuable properties of the acetate silk 
are not impaired in any way. They give very pure, bright and 
bloomy shades, and their fastness properties meet the usual re- 
quirements. However, they will not withstand cross-dyeing and 
usually stain other fibers present in the dye bath. In Table XXV 
which follows, the dyes starred possess a good fastness to light. 
In order to obtain the desired results, it is essential that the dye- 
ing instructions, as given in Method No. 37, be followed closely. 

Method No. 37: The Setacyl and Setacyl Brilliant Dyes on Ace- 
tate Silk. About a 30 to 1 dye bath should be prepared with the 
necessary quantity of dyestuff, calculated on the weight of the 
goods, and with gelatin or glue, as given in Table XXV, based 
upon the volume of dye bath in liters. The dyestuff should be 
dissolved in acetic acid before adding it to the dye bath, using a 
volume of acid in cubic centimeters equal to one-half of the weight 
of the dye in grams. Enter the previously thoroughly wet-out 
acetate silk at about 55° C. (131° F.), for light or medium shades, 
or at 65 to 70° C. (149 to 158° F.) for dark shades. Dye the 
goods for about 10 minutes, then remove the goods and add the 
first portion of Setacyl Salt A, as given in Table XXV, in solu- 
tion. Mix well, re-enter the goods and dye for about 15 minutes. 
Add the second portion of Setacyl Salt A, always in solution, 
and continue the dyeing. After about 10 minutes more, the third 
portion of the Setacyl Salt A may be added, if necessary. 

The whole dyeing operation usually requires about an hour for 
medium shades. Darker shades require a longer time, and black 
about 2 hours. After dyeing, the acetate silk should be rinsed 
and then soaped for 3 minutes in a cold bath containing 2 grams 
of soap per liter. This soaping is very important as it improves 
the fastness to rubbing. After soaping and brightening with 
formic acid, the material should be dried without previous rins- 
ing at a temperature not exceeding 30 to 40° C. (86 to 104° F.) 


Yen) 


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VY LIVS TAOVLES HLIA\ SHAQ INVITMYAG TAOVLAS GNV TAOVLAS AHL. ONIA TV 
AX SUAVE 


160 ACETATE SILK 


Patented Methods of Dyeing by Precipitation 

The first patent covering the application of dyestuffs to acetate 
silk by precipitation appears to be that of Ledward and Company, 
Harrison, and Burgess, British Patent No. 179,384, March 21, 
1921. According to this patent the acetate silk is dyed with a col- 
loidal dye solution prepared by adding to a solution of the dye, or 
its leuco compound, a protective colloid such as gelatin, casein, 
saponin, starch or their hydrolytic products ; followed by a precip- 
itant (except metallic chlorides), preferably a precipitant which 
is absorbed by acetate silk. Suitable precipitants are: for basic dyes, 
a weak alkali such as ammonia; a salt of an acid metallic oxide, 
such as molybdates, tungstates, or stannates; or an organic com- 
pound of acid character, such as tannic acid or salts of phenol, 
naphthols, aromatic acids, hydroxy acids, sulfonic acids, etc.; for 
acid or direct cotton dyes, a salt of an organic base such as ani- 
line, benzidine, dianisidine, phenylenediamine, naphthylamine, etc. 

Sulfur dyes are dissolved in sodium sulfide, hydrosulfite, etc., 
and the vat dyes in sodium hydrosulfite, the same precipitants being 
used as in the case of direct dyes. Mixed goods containing cotton 
may be dyed with sulfur or vat dyes as described above, the cotton 
threads being subsequently colored with direct dyes. The pro- 
visional specification describes the use of salts of ammonium, 
barium, magnesium, etc., as precipitants for direct and acid dyes, 
and of oxidizing agents, such as air or metallic salts, as precipi- 
tants for vat and sulfur dyes; it also refers to the use of alizarine 
dyes, using metallic salts, mordants, or organic substances as 
precipitants. 


Indigo on Acetate Silk 


For example, 100 grams of acetate silk are worked for five min- 
utes in a bath containing 2 grams of indigo, 8 grams of caustic 
soda, 5 grams of sodium-hydrosulfite, 2 grams of glue, and 2 
liters of water at 60 to 70° C. (140 to 157° F.). A solution of 
0.5 gram of dianisidine in 4 cubic centimeters of glacial acetic 
acid and 200 cubic centimeters of water is then added in successive 
small quantities. The goods are removed from the dye bath and 
oxidized in the air. This process is more satisfactory for vat and 


Dy BiNG BY PRECIPITATION 161 


sulfur dyes than with the direct cotton dyes, as the latter are not 
fast to soap and alkalies when applied by this method. 


Basic and Direct Dyes by Precipitation 


The example given for basic dyes states that 100 grams of ace- 
tate silk may be dyed in a 2 liter bath containing 1 gram of Ma- 
genta, or 2 grams of Methylene Blue, and 2 grams of glue, raising 
the temperature to 70 or 80° C. (158 to 176° F.). A solution of 
2 grams of sodium stannate in 200 cubic centimeters of water is 
then added gradually, while working the fiber. Saponin may re- 
place the glue, and tannic acid the stannate. Diamine Sky Blue 
and other, direct cotton dyes are applied in the same manner, only 
adding 0.5 gram of dianisidine base in 2 cubic centimeters of 
glacial acetic acid diluted with 200 cubic centimeters of water, 
in place of the sodium stannate solution. 

British Patent No. 213,593, March 27, 1924, and French Pat- 
ent No. 574,416 to J. R. Geigy very possibly covers Setacyl Salt 
A and the application of the Setacyl dyes. This patent supersedes 
British Patent No. 179,381. It states that acetate silk may be dyed 
by immersion at a temperature of 45 to 50° C. (113 to 122° F.) 
in an aqueous bath containing a dyestuff having little or no affinity 
for acetate silk, but which is precipitated by the addition of suit- 
able aromatic substances, preferably in the presence of a pro- 
tective colloid. Alternatively, the acetate silk may be previously 
treated with a solution of the precipitant, squeezed, and immersed 
in the solution of the dyestuff. Suitable precipitants include the 
sulfonic acids of benzene, naphthalene (B-naphthalene sulfonic 
acid) and anthraquinone, the salts of these acids and their hy- 
droxy, alkyl, chloro, and nitro derivatives. Aromatic carboxylic 
acids, such as salicylic acid, may also be used as precipitants, and 
glue and gelatin as the colloid. 

For example: acetate silk may be dyed by immersion in a dye 
bath containing 2 per cent of Methylene Green and 2 per cent of 
sodium diphenylaminesulfonate; or 2 per cent of Auramine O 
and 2 per cent of sodium o-cresotate; or 2 per cent of Martius 
Yellow, 4 per cent of gelatin and 2 per cent of benzoic acid; B- 
naphthalenesulfonic acid and gelatin with Magenta; or B-anthra- 


162 ACEH TAT iOs Maid 


quinonemonosulfonate and gelatin with Pyronine G, in a 60 to 1 
dye bath. 

British Patent No. 231,897, March 27, 1924, to J. R. Geigy, 
states that acetate silk may be printed with a paste containing aro- 
matic sulfonic or carboxylic acids or their substitution products, 
or a salt of such an acid, and a dye which has only a slight affinity 
for this fiber. Protective colloids may also be included in the 
paste. By an alternative method, the acetate silk may be satur- 
ated with a solution of one of the acids mentioned, then dried and 
printed with the dye paste. 

For example, 1 part of 2-napthol-7-sulfonic acid is dissolved 
in 13 parts of warm water and mixed with 36 parts of gum 
thickening. This is mixed with the color paste prepared from 1 
part of Setoglaucine, 5 parts of 80 per cent acetic acid, 10 parts of 
water, and 34 parts of gum thickening. The prints are steamed 
and washed. Other suitable acids are the sulfonic acids of ben- 
zene, naphthalene or anthraquinone, salicylic acid and the hydroxy, 
alkyl, chloro, and nitro derivatives of these acids. 


CHAPTER XII 
MORDANTING ACETATE SILK 


Ir is well known that the usual mordants, such as tannin and 
the common soluble salts of iron, aluminum, and chromium are 
not applicable to acetate silk as bottoming mordants, by the usual 
methods. However, as mentioned in Chapters X and XI, certain 
other inorganic and organic compounds are used as assistants in 
dyeing for certain effects. Recently several methods of mordant- 
ing this fiber by means of special salts, not ordinarily used as mor- 
dants, have been patented and may have a certain field of useful- 
ness for various purposes. 

French Patent No. 563,785, which was issued recently, states 
that when acetate silk has been treated with certain metallic salts, 
it has a greater affinity for dyes and that they penetrate better. 
Various tin salts, especially the chloride and bichloride, are recom- 
mended. 

Method No. 38: Mordanting Acetate Silk with Tin. For ex- 
ample, one hundred grams of acetate silk may be treated in a bath 
containing 800 cubic centimeters of 20° Be. (1.16 sp. gr.) tin 
bichloride solution. After washing with water, it is treated with 
a 2° Be. (1.014 sp. gr.) sodium silicate solution. A second treat- 
ment at 40° C. (104° F.) is then given and the fabric washed. 
This treatment is claimed to have no detrimental effect on the 
acetate silk. 

Method No. 39: Mordanting Acetate Silk With Aluminum. The 
Lustron Company? states that Lustron may be mordanted with 
aluminum by treating it overnight in a solution containing 8 
parts of 8 to 10 Tw. (1.04 to 1.05 sp. gr.) aluminum acetate and 
2 parts of glacial acetic acid. In the morning it should be hydro- 
extracted, rinsed lightly once, and then dyed with alizarine or 
other suitable mordant dyes. A final treatment of the dyed ace- 
tate silk, consisting of Turkey-red oil, soda, and ammonia, is 
recommended. 3 


163 


164 ACETATE SILK 


The most recent patent along this line appears to be that of the 
British Dyestuffs Corporation, L. G. Lawrie and H. Blackshaw, 
British Patent No. 240,293, September 23, 1924. This states that 
acetate silk is capable of absorbing certain metallic mordants such 
as chromium, aluminum, or iron (ous), from their aqueous solu- 
tions provided the metal is present as a thiocyanate, benzoate, 
salicylate, phthalate, or other aromatic carboxylate or hydrocar- 
boxylate, and may then be dyed by means of an appropriate dye- 
stuff. Acids, alkalies, or other assistants can be used to assist the 
absorption of the salts by the acetate silk. 

Method No. 40: Mordanting Acetate Silk by Organic Salts of 
the Metals. For example, the acetate silk may be treated for an 
hour at 75° C. (167° F.) in a 15° Tw. (1.075 sp. gr.) solution of 
aluminum thiocyanate. It is then treated for 5 minutes at 35° ce 
(95° F.) with a 1 per cent solution of sodium carbonate, rinsed, 
and dyed in a bath containing 7.5 per cent of 20 per cent Alizarine 
IP 20 per cent paste and 0.5 per cent of chalk, for an hour at 
25° C. The dyed fabric should be soaped. The resulting bright 
red color is the same as the usual aluminum lake of alizarin. By 
similar methods a pale lilac shade may be obtained with chromium 
thiocyanate and Anthracene Blue BDG (C. I. No. 1059); a 
black color with iron thiocyanate and Haematine; or a bluish- 
violet color with chromium salicylate and Chromazol Violet (C. 
I. No. 892). Obviously many other combinations of mordants 
and dyes may be made to give a wide variety of fast colors of 
good depth of shade. Possibly the method may also be useful in 
increasing the fastness of the mordant dyes which have an affinity 
for this fiber. In this case the color could be top-mordanted. 
Davies! states that the process is not very successful on a com- 
mercial scale. 

British Patent No. 215,012, April 26, 1924, to the Société 
Alsacienne de Produits Chimique covers the production of sul- 
furized phenols, completely soluble in aqueous solutions of sodium 
carbonate and suitable for use as mordants for basic dyestuffs, 
by heating a mixture of phenol, sulfur, and a small proportion of 
iodine, the last named acting as a catalyst. For example, 188 
grams of phenol, 107 grams of sulfur and a small amount of iodine 


MORDANTING ACETATE SILK 165 


are heated at 190° C., then at 210° C. for 4 or 5 hours, or until 
the evolution of hydrogen sulfide ceases. The viscous product is 
then cooled and powdered. 

British Patent No. 224,218, October 18, 1924, to the same com- 
pany, an addition to patent No. 215,012, covers the use of sul- 
furized phenol, its derivatives, or substitution products, as de- 
scribed in the previous patent, in place of tannin, for mordanting 
rayon. With basic dyes the colors obtained are nearly the same 
as on a tannin antimony mordant, and treatment with antimony 
is not necessary. The mordanting operation may take place in 
the same bath and concurrently with the application of direct or 
sulfur dyes, which are to be topped with basic dyes. In an ex- 
ample, acetate silk is treated in a bath containing the mordant, 
sodium hydroxide, and sodium phosphate, washed and dyed with 
a basic dye. From this example it would appear that this mordant 
is more applicable to the saponified acetate silk than the normal 
fiber. 

Roetel? mentions a Badische “Mordant for Acetate Silk” about 
which little appears to be known in America. Also see Mordant 
LB in Chapter XIX, on the saponification process. 


References 


1H. R. Davies, American Dyestuff Reporter 15, 199 (1926). 

2Tustron Company, “Recommendations for Finishing and Dyeing Fabrics 
Containing Lustron Silk.” 

8B. Roetel, Tertilber. Jan. 1926; translation American Dyestuff Re- 
porter 15, 387-8 (1926). 


CHAPTER (XI 
THE ACID AND MORDANT DYES ON ACETATE SILK 


The Setacyl Direct, Cellit Fast, Cellutyl, and Acetate Dyes 


THE classification of the older types of dyes for use upon cotton, 
wool, and true silk is not usually difficult, but with the advent of 
acetate silk a new factor entered upon this classification. Many of 
our older “acid” dyes are applied as “direct” dyes to acetate silk, 
while the bulk of the older acid and direct dyes have no affinity 
at all for the unhydrolyzed acetate silk. In the same way, many 
of the older mordant dyes also have a direct affinity for acetate silk 
and may be applied to it by methods similar to those used in apply- 
ing the older direct dyes to cotton and the older rayons. 

Now come along many of the new dyestuffs, the products of 
research upon acetate silk, and produced particularly for use upon 
it. Many of these new products are azo compounds containing 
acid groups, which, under the older methods of classifying the 
dyestuffs, would certainly be classed as acid dyes, yet they are _ 
applied to acetate silk by “direct’’ methods or the dispersol process.* 
Some few of these new azo dyes also have a slight affinity for 
cotton, but possibly none of them would come under the older 
classification of direct cotton azo dyes. Others of the new prod- 
ucts, especially the anthraquinone compounds, resemble dyes of 
the older acid mordant and mordant classifications, such as some 
of the Acid Alizarine dyes. These, too, are sometimes applied by 
direct and dispersol methods to acetate silk. 

From this it appears that the dyes which have an affnity for 
acetate silk will have to have a new and separate classification when 
used upon this fiber. Perhaps the first step in this line was the 
entirely new classification known as the dispersol dyes. However 
if we adhere to the older classification of acid and mordant dye- 
stuffs, but include in it the new azo and anthraquinone products 
which are applied by direct methods, and which appear to fall 


“See Chapters XXI, XXII, and XXIII. 
166 


THE ACID AND MORDANT DYES 167 


within this scope, we have a very large, important, and rapidly 
growing group of dyes applicable to acetate silk by very simple 
methods, with excellent results. 

The announcement of the dispersol type of dyes for acetate 
silk created considerable comment in the textile and dye field, 
which was certainly well deserved on account of their unique 
originality. While many of the new products which are here 
classified as acid and mordant dyes are just as useful in dyeing 
acetate silk as the dispersol dyes, they have not created nearly as 
much comment in the trade, because their theory and method 
of application is not entirely new. Many of these products have 
appeared upon the market recently, and undoubtedly some of them 
will eventually find a wide usefulness upon this fiber. 

As discussed in Chapter VIII, acetate silk has no affinity for 
most of the older acid dyes, but some of them, particularly those 
which do not contain sulfonic acid groups, or only one sulfonic 
group, which may be counteracted by the presence of other groups, 
are applicable. While acetate silk has no affinity for the usual 
mordants, such as the common salts of iron, chromium, and 
aluminum, many mordant dyes may be applied to it without a 
mordant by virtue of their phenolic and ketonic functions. Where 
a mordant is desired for any particular reason, it may be applied 
as in Chapter XII. In using mordants on acetate silk it should be 
remembered that the color produced by most mordant dyes usually 
varies somewhat with the particular mordant used and even more 
when it is applied without a mordant. 

It is well known that the sulfonic acid radicle confers solubility 
in water to many otherwise insoluble dyes and other organic com- 
pounds. At the same time, the sulfonic group decreases the solu- 
bility of the sulfonated compound in organic solvents. It has been 
pointed out by several investigators that the dyeing of acetate silk 
in many ways appears to resemble a solution phenomenon, such as 
the solution of the dye in an organic solvent; as, for instance, a 
hydrocarbon oil. Therefore we can readily see why the sulfonic 
acid group is not always desirable in dyes for this fiber. On the 
other hand, carboxylic acid groups also confer solubility in water 
upon many organic compounds, including dyes, without at the 


168 ACETATE SILK 


same time so materially reducing the solubility of the carboxylated 
compound in organic solvents or acetate silk. At the present time 
it is impossible to classify all of the various new acetate silk dyes, 
but it is highly probable that some of the new products in powder 
form, as, for instance, the Setacyl Direct dyes, may be carboxy- 
lated aminoazo compounds. 

The extent to which the sulfonic group or groups affect the solu- 
bility of the sulfonated compound in acetate silk, and possibly 
other organic solvents, depends not only upon the number of sul- 
fonic groups present, but also upon their orientation, as well as 
the other radicles present in the molecule.? For this reason it is 
possible to apply certain monosulfonated dyes to acetate silk, which 
possibly most nearly resemble acid or mordant dyes in com- 
position. 

Some of the simpler anthraquinone derivatives, such as those of 
the alizarine series of dyes, are solubilized by sulfonating either 
the anthraquinone nucleus or attached arylamino groups. This 
principle is possibly used in the production of certain acetate silk 
dyes. However, when the more complex anthraquinone deriva- 
tives, such as the vat dyes are sulfonated, their solubility is de- 
creased instead of increased. The carboxylic acid and certain 
basic groups which have been used in solubilizing some other 
classes of dyes are of little use in solubilizing the more complex 
anthraquinone derivatives. Indanthrene Blue WB (CIS eNG: 
1093) is a sulfonated anthraquinone vat dye which is somewhat 
soluble in hot water. While some of the dyestuffs used in the 
preparation of the dispersol type of paste dyes may be either sul- 
fonated or unsulfonated azo compounds, the former resembling 
acid dyes in constitution, the more soluble anthraquinone com- 
pounds more nearly resemble the mordant dyes, and the compara- 
tively insoluble products often approximate the vat dyes in consti- 
tution. 

Perhaps the greatest advantages of the acid and mordant dyes 
over the basic dyes on acetate silk are their greater fastness to 
light and better leveling properties. As explained before, the 
affinity of the basic dyes for acetate silk possibly resides in the sul- 


>’ See British Patent No. 226,948. 


THE ACID AND MORDANT DYES 169 


fate and acetate groups of the cellulose acetate molecule, and there- 
fore any irregularity in the chemical constitution of the acetate silk, 
due either to acetylation or hydrolysis, renders it impossible to se- 
cure level shades with some basic dyes, while the trouble is even 
more aggravated with many of the special acetate silk dyes. Usually 
the acid and mordant dyes are not so sensitive in this respect, and 
therefore it is sometimes possible to obtain level shades on dam- 
aged or inferior goods with them. Usually the older acid dyes do 
not have sufficient affinity to give heavy shades on acetate silk, 
but this does not apply at all to the new dyes of this type prepared 
especially for acetate silk. 

It is interesting to note, as mentioned in Chapter VIII, that 
in some cases the free color acid of the acid dye dyes the acetate 
silk a deeper shade than the sodium salt of the dyestuff, as in the 
case of Eosine I, Toluylene Orange, Acid Ponceau, etc. This only 
occurs when the free color acid is less soluble in water than its 
sodium salt. In the same chapter it was also mentioned that in 
some cases the affinity of the acetate silk for the basic portion of 
certain dyes, usually amino compounds, is sufficient to cause a 
partial decomposition of the dyestuff molecule, the basic portion 
entering the acetate silk. 

While all dyes of the acid and mordant classification which 
have an affinity for acetate silk are very easy to apply to this fiber, 
the older members of this group have been almost wholly dis- 
placed for use on acetate silk by the newer members prepared 
especially for use on this fiber, and the Ionamine and dispersol 
type of dyes. These new dyes, while still retaining the ease of 
application of the older and better known acid and mordant dyes, 
offer many other advantages, such as deeper shades, a wider 
range of colors of greater fastness and brilliancy, etc., so that there 
is at present no reason to continue the use of the older dyes, which 
were really only makeshifts on acetate silk, except for special 
purposes. However, as the acid and mordant dyes are used on 
many other fibers in combination with acetate silk, their properties 
in regards to acetate silk are highly important. Then, too, some 
members of this classification are still used in printing and dis- 
charge work, etc. 


170 ACETATE SILK 


The dyes of this class which are applicable, whether of the older 
group or the new special dyes for acetate silk, are frequently 
applied to acetate silk in light shades from a bath containing only 
soft water and the dyestuff. A neutral salt, such as sodium chlor- 
ide or sulfate, is usually added to the dye bath, where heavy shades 
are desired, in order to aid the exhaustion, the action in this case 
being just the reverse of that in the basic dye bath, where it acts 
as aretard. In fact many of the formulas which are used for the 
basic dyes on acetate silk are used for the acid dyes also. In this 
way Methods No. 24 to No. 27 given under the basic dyes in 
Chapter X are recommended for the application of the acid dyes. 
Probably Method No. 24 is more practical. Method No. 41, 
which resembles Method No. 27, is also suggested for the ap- 
plication of acid and mordant dyes, but may be used for the basic 
dyes. 

Method No. 41: Acid, Mordant, and Basic Dyes on Acetate 
Silk with Ammonium Salts. Use a 20 to 1 dye bath containing 
15 to 30 per cent of ammonium chloride, according to the amount 
of dye used, to accelerate the exhaustion of the acid or mordant 
dyestuff. Enter the goods at 40° C. (105° F.), add the ammonium 
salt and gradually raise the temperature to 71 to 74° C. (160 to 
165° F.) for one hour. The dyed goods should be rinsed and 
soaped for 10 minutes at 25 to 30° C. (77 to 85° F.) in a bath 
containing 2 pounds of soap per 100 gallons of liquor. This 
method has been particularly recommended for dyeing cotton- 
acetate silk unions with acid or mordant and direct cotton dyes. 

The “mordanting” effect of certain acid dyes for the basic dyes 
was mentioned in connection with the basic dyes and this is the 
basis of an increased usefulness of both acid and basic dyes on 
acetate silk. The resulting shades are frequently much faster to 
water and washing than either of the component colors alone. 
It is also useful in obtaining deeper shades with the basic dyes, 
which, of course, also means a better exhaustion of the dye bath. 
Method No. 44 covers such a topping process and Table XXVI 
gives a list of a few of the innumerable colors obtainable by this 
process. 


MPEP 


aie ee we; 


fell) AND MORDANT DYES saya 


? 


Azo Dyes 

The azo dyes include many acid, direct cotton, and mordant 
dyes, some of which may be applied to acetate silk, possibly due 
to the basic character of the azo group. As mentioned before, 
those containing sulfonic acid groups, such as Benzopurpurin 
4B (C. I. No. 448), Chlorazol Black E extra and Diamine Black 
BH (C. I. No. 401), are not suitable. Fast Oil Orange I (ben- 
zeneazo-B-naphthol, C. I. No. 24) gives satisfactory shades on 
acetate silk. In the case of Metanil Yellow, Orange IV, Silk 
Ponceau G (C. I. No. 196, sodium salt of 5- and 8-sulfo-B- 
naphthaleneazo-B-naphthol), and Brilliant Orange G (C. I. No. 
26, sodium salt of benzeneazo-B-naphthol-6-sulfonic acid), the 
adverse action of the sulfonic acid group 1s partially overcome. 

Diazo dyes, such as Pyramidol Brown BG and Bismark Brown 
may be used, but the latter does not usually give very deep shades 
on acetate silk. Some sulfonated azo dyes, chiefly yellows, or- 
anges, and reds, as for instance Roccelin, may be dyed directly on 
acetate silk. Clavel suggested the addition of a small quantity of 
aniline hydrochloride to the dye bath when applying the simple 
monoazo dyes. Some azo dyes which contain no sulfonic groups 
but which are slightly soluble in water, as for instance Terra 
Cotta RS and Azochromine (tetrahydroxyazobenzene, C. I. No. 
95) and their equivalents, may be used. Azo Yellow I is fast to 
light and useful as a bottom color for emerald and jade greens 
when topped with basic green or blue. Alizarine Yellow 3G and 
Alizarine Orange R may be after-treated with chrome if de- 
sired. 

Azochromine gives a brown color and there are other browns 
which give more or less fast shades when fixed by after-chroming, 
as in Method No. 36. Alliance Fast Brown 5G paste? has excep- 
tional fastness to light and a good fastness to acids, alkalies, wash- 
ing and rubbing. Brotherton’s Metachrome dyes are useful. 
Rose Pink CA58 belongs to this class, while Chromocitronine, 
Chromoxanthine (C. I. No. 40) and Chrome Deep Brown RR are 
also used. Azo Yellow Conc., Orange IV, Alizarine Direct Vio- 
let ER, Alizarine Direct Blue A and SE, and Acid Alizarine Gray 
B will stain the cotton in cotton-acetate silk unions to some extent. 

A recent paper by Hall and Aische! gives some very interesting 


172 ACETATE SILK 


information regarding the affinity of various azo dyes for acetate 
silk, as compared to cotton and wool, as well as some new sugges- 
tions regarding the solubilization of azo dyestuffs for use on ace- 
tate silk and other fibers. Hall and Aische point out the fact that 
most of the dispersol dyes should be applied in an alkaline bath, 
which is a very decided disadvantage where they are used in con- 
nection with acid dyes, as on acetate silk-wool unions, by the one- 
bath method. On account of the retarding action of the sulfonic 
groups, as well as the carboxylic-acid groups to a smaller extent, in 
dyes for acetate silk, they propose to utilize arsinic (AsO(OH)2) 
and stibinic (SbO(OH).) acid groups to solubilize suitable azo 
dyes for application to acetate silk from an acid or neutral dye 
bath. They prepared the sodium salts of the sulfonic, carboxylic, 
arsinic and stibinic acids of a-naphtholazophenol, B-naphthol- 
azophenol, phenolazophenol, and salicylic acid azophenol. Table 
XXVI gives the colors obtained upon acetate silk in both acid and 
alkaline solutions, as compared with wool and cotton. 

From experiments upon the application of these dyes and upon 
the fastness to boiling water, boiling soap and ammonia solution, 
and light, they conclude that: 


a. Acetate silk and cotton have but little, and wool considerable 
affinity for the azo compounds described. All of the colors 
on wool have approximately equally good fastness to boiling 
water but have little fastness to boiling soap. Azo com- 
pounds containing sulfonic, carboxylic, and arsinic acid groups 


have approximately equal fastness to light, whereas, azo 


compounds containing stibinic acid groups are considerably 
less fast. 


b. Azo compounds containing stibinic acid groups have a greater 
affinity than those corresponding compounds containing ar- 
sinic acid groups for acetate silk, but these differences cannot 
be correlated to differences in the solubilities of the azo com- 
pounds in water. 


c. Azo compounds containing B-naphthol have a greater affinity 
for acetate silk than those containing a-naphthol. This 1s 
supported by other unpublished work by Hall and Aische. 


—" 


real AND MORDANT DYES 173 


d. The differences shown in the affinities of phenylazophenol- 
4-stibinic acid and salicylic acid azophenol-4-stibinic acid agree 
with the general observation that acetate silk has a decreasing 
affinity for azo compounds containing carboxyl and hydroxyl 
groups. 

e. The affinity of acetate silk for azo compounds containing sul- 
fonic, arsinic, stibinic and carboxylic acid groups increase in 


the order named. 


TABLE XXVI 
CoLors OBTAINED ON ACETATE SILK, WOOL, AND SILK WITH VARIOUS AzO 
DYESTUFFS SOLUBILIZED BY SULFONIC CARBOXYLIC ARSINIC 
AND STIBINIC ACID GROUPS 


Color On 
Dyestuff as Sodium Salt of Wool Cotton Acetate silk Acetate Silk 
Alkaline Acid 
a-Naptholazophenyl-4-sulfonic Deep brown Stained Stained pink 
acid bluish pink 
B-Naphtholazophenol-4-sulfonic Bright Stained Pale orange oe 
aci reddish-orange pink 
ee opnenys-2sulfonic Bright yellow Unstained Unstained id 
aci 
Salicylic acid azophenyl-4- Bright yellow Unstained Unstained a 
sulfonic acid 
a-Naphtholazophenyl-4-car- Yellowish- Pale pink Stained ee 
boxylic acid brown yellow 
B-Naphtholazophenyl-4-car- Bright scarlet Pale orange Pale orange _ 
boxylic acid 
ee nw t-catborylic Yellow Unstained Unstained — 
aci 
Salicylic acid azophenyl-4-car- Dull yellow Stained Unstained — 
boxylic acid yellow 
a-Naphtholazophenyl-4- Dullyellow- Pale yellow Unstained Deep reddish 
arsinic acid ish-brown yellow 
B-Naphtholazophenyl-4- Bright orange Stained Stained Deep orange 
arsinic acid orange orange 
Be peeny)-f-ersinic Pale yellow Unstained Unstained Yellow 
aci 
Salicylic acid azophenyl-4- Dull yellow Unstained Unstained Greenish- 
arsinic acid yellow 
a-Naphtholazophenyl-4- Reddish- Pale pink Pale orange Stained 
stibinic acid brown brown 
Naphtholazophenyl-4- Yellowish- Pale orange Pale orange Deep orange 
stibinic acid orange é 
Phenylazophenyl-4-stibinic Yellow Pale yellow Pale yellow Stained 
acid yellow 
Salicylic acid azophenyl-4- Yellow Pale yellow Unstained Stained 
stibinic acid yellow 


Nitro Dyes 

Nitro dyes such as Picric Acid and Martius Yellow (salt of 
2, 4-dinitro-a-naphthol, C. I. No. 9) may also be used on acetate 
silk, but the shades are not of much importance. As Naphthol 
Yellow S (salt of 2, 4-dinitro-a-naphthol-7-sulfonic acid, C. I. No. 
10) is sulfonated, it cannot be used. Hall*® states that the nitroso 
dyes, Gambine Y (a-nitroso-B-naphthol, C. I. No. 2) and Alsace 
Green N (dinitrosoresorcinol, C. I. No. 1), obtained by the action 


174 ACETATE SILK 


of nitrous acid on B-naphthol or resorcinol, respectively, are ab- 
sorbed by acetate silk but have little tinctorial power except as 
iron lakes, so that they are of little practical value. 

Of the remaining older and better known acid and mordant dyes 
which are applicable to acetate silk, Alizarine Orange AO (nitro- 
alizarine, C. I. No. 1033) is very useful, Alizarine Garnet (C. I. 
No. 168) is not much changed by soaping. Alizarine Green ae 
and Alizarine Blue S and ABS (C. I. No. 1067) are also used, 
the former for gray, and the latter for a light fast reddish-blue. 
Emmons! states that true Alizarine may be dyed on acetate silk 
from a bath of pure water only. Khaki Yellow WN? (C. I. No. 
36) gives shades of good fastness from a salt bath but acids 
weaken the shade. Alizarine Yellow WS is useful for gold shades 
and in combination with other acid dyeing colors. It has good 
fastness properties, particularly to light and is applied with salt 
and acetic acid. Orange IV (C. I. No. 148) is fast to light, 
alkalies, and rubbing but is sensitive to acids. 

Metanil Yellow Y (C. I. No. 138) has a fastness similar to 
Orange IV and is applied from a salty dye bath. Anthracene 
Brown WL (C. I. No. 1035) is useful for olive yellows and is 
applied by means of salt and acetic acid, as in Methods No. 25. 
It has good fastness properties, particularly to light, but is dulled 
by alkalies. Alizandine Orange M paste (C. I. No. 40) is dyed 
with salt and has good fastness. Citronine Y Conc. gives bright 
golden yellows from a neutral salt dye bath. It has good fastness 
properties but becomes orange in the light. Cloth Reds are use- 
ful for fast pinks and may be applied with other neutral or acid 
dyeing colors. Acid Rhodamine 3R, Coomassie Fast Violet 10BP 
and Indian Yellow GA or Azo Yellow A5W (C. I. No. 146) are 
also used. They are applied with acetic acid or 10 to 15 per cent 
of salt, as in Method No. 25. Coomassie Fast Violet is only mod- 
erately fast to light and the Indian Yellow reddens in shade but 
is fast. 

Azo Yellow Conc., Acid Alizarine Gray B, Amido Yellow E 
(C. I. No. 11). Alizarine Direct Blue A and SE, Orange IV, 
Alizarine Direct Violet ER and R (C. I. No. 1074), Autochrome 
Olive Brown G Conc., and Chrome Blue BMI Conc., are also ap- 


feel) AND MORDANT DYES 175 


plicable to acetate silk. The acid dyes of this group, as well as 
Acid Alizarine Gray B and Autochrome Olive Brown G are of 
good fastness to washing, and are fast to acid, with the exception 
of Orange IV and Autochrome Olive Brown G, which change 
shade temporarily. This also applies to Victoria Yellow O (C. 
I. No. 188) which gives a fine yellow fast to light on acetate silk. 
Alizarine Yellow 2GW (C. I. No. 36) and RW (C. I. No. 40) 
may also be applied to acetate without after-chroming but do not 
give full shades. 

Orange II (C. I. No. 151), Brilliant Orange O (C. I. No. 63) 
Boer oie ocatict © (C. 1. No. 193), and Fast Red O (C. I. 
No. 176), give fairly full shades on acetate silk but are not very 
fast to light. Amido Yellow E, Orange IV, Alizarine Direct 
Violet R and ER, Alizarine Direct Blue SE, Modern Violet, 
Violet PDH, Prune Pure, Indian Yellow, Alizarine Yellow 3G, 
and Alizarine Orange R, are particularly fast to light. The 
light fastness of Azo Yellow, Acid Alizarine Gray B and Auto- 
chrome Olive Brown B is good. Chrome Blue BMI is very fast 
to washing and light, but should not be used in large quantities 
in the same dye bath with other dyes. Chrome Orange R 
(p-nitrobenzeneazosalicylic acid, also known as Alizarine Yellow 
R and Alizarol Orange R), and Pontachrome Yellow 3R are also 
useful on Lustron. Certain basic dyes such as Victoria Green 
WB and Methylene Green B may be used in the same bath with 
many chrome dyes. Topping certain of the acid dyes with basic 
dyes may improve the fastness to water and washing in some in- 
stances. 

The following acid and mordant dyes of the older classification 
may also be applied to acetate silk directly by Method No. 24: 


Yellow Amido Yellow E 

Azoflavine S Fast Yellow G and GL 
New Yellow ‘ Fast Light Yellow G and 3G 
Citronine Y and G Indian Yellow G, R, and GA 
Azo Yellow Conc., I and A5W Anthracene Yellow C 
Victoria Yellow O Era Chrome Olive 
Alizarine Yellow GG, 3G, 2GW, Khaki Yellow WN 

R, RW, and WS Metanil Yellow Y 
Terracotta RS Pontachrome Yellow 3R 
Tropaeoline G Chromocitronine 


Quinoline Yellow | Martius Yellow 


va) 


Orange 


ACETATE SiLk 


Blue 


Orange II, IV, RO, G, GG, and Chrome Blue BMI Conc. 


Extra 
Golden Orange 
Pontachrome Orange 
Tropaeoline OO and OOO 
Alizarol Orange R 
Chrome Orange R 
Brilliant Orange O, G, and M 
Oxychrome Orange RW 
Brilliant Orange M, O, and G 
Monochrome Orange R paste 
Alizarine Orange AK and R 
Azo Orange AO 
Alizandine Orange M paste 
Chromoxanthine 


Red and Pink 


Cloth Red B and G 
Rocelline 

Cerasine 

Acid Rhodamine 3R 
Ponceau G and GR 
Silk Scarlet O 

Fast Red A and O 
Xylidine Red 

Alizarine Garnet 

Acid Scarlet 4R 

New Ponceau 4R 

Azo Acid Cardinal 
Fast Red A and A new 
Rhodamine B 

Eosine Crimson 2B 
Alizarine Bordeaux paste 
Archil Substitute 
Alizarin Garnet 

Rose Pink CA58 
Cardinal Red J 


Violet 


Fast Violet DH (Gallocyanine dye) 
Gallocyanine D (Gallocyanine dye) 


Alizarine Direct Violet ER and R 


Alizarine Cyanol Violet R 
Alizarine Maroon 

Brilliant Milling Violet S4B 
Brilliant Chrome Violet 4BR 
Chrome Violet G 
Coomassie Fast Violet 10BP 


Soluble Blues 

Celestine Blue 

Brilliant Alizarine Blue G 
Alizarine Blue S and ABS 
Alizarine Direct Blue A and SE 
Alizarine Brilliant Blue B 
Alcaline Blue H5B 

Induline 5B 

Alizarine Brilliant Blue B 
Anthracene Blue 2B and 2BR 
Alizarine Cyanine AK 


Green 
Alizarine Green S 
Alsace Green N 
Gambine Y 


Brown 


Azo Brown 

Metachrome Brown B 

Autochrome Olive Brown G Conc. 

Resorcinol Brown R 

Anthracene Acid Brown B 

Naphthalamine Brown 

Fast Brown N 

Oxychrome Brown GR Extra 

Oxychrome Brown BG 

Monochrome Brown G paste and 
H paste 

pes Brown GR extra and 

Alizadine Brown M 

Anthracene Acid Brown B 

Naphthalamine Brown 

Solochrome Brown MO 

Anthracene Brown WL 

Azochromine 

Alliance Fast Brown 5G paste 

Chrome Deep Brown RR 


Gray and Black 
Acid Alizarine Gray B 
Omega Chrome Black PV 


Nigrosine B Crystals 


The Cellutyl Dyes 


A selected list of dyestuffs, possibly all well-known acid, mordant 
and basic dyes, which dye acetate silk are marketed by the Brit- 


THE ACID AND MORDANT DYES aie 


ish Dyestuffs Corporation under the Cellutyl brand. While 
these dyes, in common with all of the other older dyes belonging 
to the same classes, are not at present used on acetate silk to any 
great extent, they still find a limited use for special purposes, 
such as in discharge printing. This group of dyes includes (a) 
Cellutyl Yellow C, Cellutyl Fast Yellow AY and B, Cellutyl Fast 
Tangarine, Cellutyl Fast Orange G and R, Cellutyl Fast Golden 
Orange, (b) Cellutyl Bright Red, Cellutyl Fast Red D, Cellutyl 
Fast Lilac and 2B, and Cellutyl Sky Blue. The dyes given under 
group a stain cotton and other rayons either slightly or not at all. 
The b group stain cellulose more and possibly at least some of 
these belong to the basic class. 

Method No. 42: The Cellutyl Dyes on Acetate Silk. Most of 
the Cellutyl and Cellutyl Fast dyes may be applied by the methods 
generally used for the direct dyes on cotton, that is in a bath con- 
taining about 20 or 30 per cent of sodium chloride, at about 85° C. 
(185° F.) for an hour or less. In some cases, probably where the 
dyestuff belongs to the basic class (Cellutyl Sky Blue) it is neces- 
sary to add about 2 per cent of acetic acid also. When dyeing 
cotton-acetate silk unions, the Cellutyl dyes are frequently applied 
in the same dye bath with the direct cotton dyes. In the case of 
Cellutyl Fast Blue, the dyestuff is applied with 1 to 5 per cent of 
acetic acid. It can be aftertreated in a fresh bath with 1 to 3 per 
cent of bichromate and 1 to 3 per cent of formic acid to give violet 
shades of excellent fastness. 


The Acetate Dyes 

The Acetate dyes of Actien-Gesellschaft fur Anilin-Fabrika- 
tion are selected acid and mordant dyes which are applicable to 
acetate silk. Two to four per cent of these dyes, on the weight 
of the material, are required to give medium shades. The manu- 
facturers recommend topping these colors on the fiber with basic 
dyes, as in Method No. 44. Table XXVII gives a list of the 
shades obtainable by this topping operation. Five Acetate dyes 
are marketed: Acetate Yellow R, Acetate Orange G, Acetate 
Brown O and R, and Acetate Red A. Their fastness to water and 
washing is up to the usual requirements, and their light fastness, 


178 ACETATE Sisk 


with the exception of Acetate Red A, is good. All Acetate dyes 
may be mixed in the same dye bath. 

Method No. 43: The Acetate Dyes on Acetate Silk. These 
products should be applied in a 20 or 30 to 1 dye bath containing 
10 to 15 per cent of Glauber’s salt crystals and 4 to 6 per cent of 
30 per cent acetic acid at 60 to 71° C. (140 to 160° F.) for an 
hour or less. This method applies to all Acetate dyes except 
Acetate Brown O, which must always be applied with only 15 to 
20 per cent of Glauber’s salt, without acid, either when dyed alone 
or in combinations. After dyeing, rinse well and dry at 49 to 60° 
C. (120 to 140° F.). 

Method No. 44: Topping the Acetate Dyes with Basic Dyes 
Enter the dyed and rinsed acetate silk in a fresh 30 or 40 to 1 dye 
bath containing 1 or 2 per cent of 30 per cent acetic acid and dye at 
60° C. (140° F.). After dyeing, rinse, brighten by soaping if 
necessary, hydroextract and dry at 49 to 60° C. (120 to 140° F.). 


TABLE XXVII 


CoLors OBTAINED WITH THE ‘‘ACETATE”’ DyES TOPPED WITH Basic Dyes 
ee eee ee eee eee nena e 


Formula Color Acetate Dye Topped With 
No. 
1 Moss Rose 5% Acetate Red A .01% Rubine Small Crystals 
2 Orange Pink 2% Acetate Yellow R .1% Rubine Small Crystals 
3 Red 3% Acetate Red A and 
.6% Acetate Brown O .3% Rubine Small Crystals 
4 Eglantine 0.2242 0% Acetate Red A .5% Rubine Small Crystals 
5 Muncio 5% Acetate Red A and 
0.7012 2% Acetate Brown R .3% Methyl Violet 6B 
6 Reddish-Violet 0% Acetate Red A and 
.2% Acetate Brown O .5% Methyl Violet 6B 
7 Mallow 0.2702 0% Acetate Red A .0% Methyl Violet 4R 
8 Greenish-Blue .15% Acetate Red A .3% Methylene Blue 2B New 
9 Light Blue .5% Acetate Red A .2% Methylene Blue 2B New 


.4% Ethyl Green Crystals 

15 %Methylene Blue 2B New 
.3% Malachite Green Crystals 
.0% Methylene Blue2B New 
.2% Methylene Blue 2B New 
.3% Methylene Blue 2B New 
.0% Methylene Gray B New 


.0% Acetate Red A 

.0% Acetate Orange G 
.5% Acetate Brown O 
.0% Acetate Yellow R 
.0% Acetate Brown R 
.5% Acetate Brown O 
.0% Acetate Yellow R 


10 Bluish-Gray 

11 Bright Brown 

12 Green 

13 Bright Grass Green 
14 Grayish-Olive 

15 Steel Blue 

16 Butterfly 0.5311 


17 Olive .0% Acetate Brown O .0% Methylene Blue 2B New 
18 Light Gray .5% Acetate Orange G .0% Methylene Gray B New 
19 Tan .0% Acetate Orange G .0% Methylene Gray B New 
20 Brown .5% Acetate Brown O .2% Methylene Gray B New 


.2% Methylene Gray B New 
.4% Crystal Violet 6B 
.1% Chrysoidine extra 


.0% Acetate Brown O 
.75 % Acetate Brown O 
.0% Acetate Orange G 


21 Brown 
22 Violet-Brown 
23 Golden Glow 0.3006 


NON FRFPONFOWNORP WRF OWOROOWOOrRF 
CDOCORRPNRFORPRFOOROORO COC FO CO 


e 
ee a ES ——<— 


~~ ee 


THE ACID AND MORDANT DYES 179 


The Setacyl Direct Dyes 


One of the most interesting and successful brands of dyes 
which possibly come under this classification are the Setacyl 
Direct dyes of the Geigy Company. These dyes are entirely dif- 
ferent in every way from the Setacyl Brilliant dyes of the same 
company which were covered in Chapter XI. The Setacyl Direct 
dyes are in powder form and are directly soluble in boiling water, 
which of course renders their use somewhat more convenient than 
that of paste products. It has been stated that they are entirely 
different from any other dyestuffs now on the market but as yet 
very little has been divulged regarding their composition. It is 
possible that they may be carboxylated, aminoazo compounds. 
They are applied to acetate silk in exactly the same manner as the 
direct dyes to cotton, that is in a neutral bath. As the usual acid 
dyes are applied in the same manner, this apparently supports 
the above speculation regarding their constitution. The fact that 
they do not appreciably stain cotton indicates that they are not of 
the direct cotton type. 

A wide range of shades are available and as they are appliéd 
at low temperatures in a neutral bath, their application leaves the 
acetate silk entirely unaltered in every way. They have good 
fastness to washing and rubbing, and withstand cross-dyeing well, 
with only a slight staining of the cotton or viscose in some cases. 
They are recommended for use in the same dye bath with the Art 
Silk Colors CW, to produce multicolor or shot effects on acetate 
silk-cotton or -rayon unions at a very low dyeing cost. 

The Setacyl Direct dyes have given excellent results in printing 
by the ordinary methods, both on acetate silk and unions con- 
taining it. While these dyes do not discharge white, the ground 
is usually sufficiently clear to give good colored discharges. Table 
XXVIII gives some data upon the fastness of the various Setacyl 
Direct dyes and at the same time serves as a list of the colors 
available. Method No. 45. covers their application to acetate silk 
and Method No. 106 to combinations of acetate silk with true silk. 

Method No. 45: Setacyl Direct Dyes on Acetate Silk. In apply- 
ing these dyes, use methods similar to those used in applying the 
direct dyes to cotton to leave true silk white. For instance, light 


180 ACETATE SICK 


shades may be obtained without using salt in the dye bath, but 
heavier shades may require from 10 to 20 per cent of Glauber’s 
salt. The goods should be entered at 38° C, (100° F.), themtem= 
perature raised to 82° C. (180° F.) in about 20 minutes, and the 
dyeing continued for about the same length of time at this tempera- 
ture. For blacks, it is recommended to start dyeing at BO te 
(140° F.), slowly raise the temperature to 75°. Ci CLGHe aia 
and run for as long as two hours. The temperature is a large 
factor in matching shades. 


TABLE XXVIII 
FASTNESS PROPERTIES OF THE SETACYL DrrEcT COLORS 


Dee Me ees 
Fastness to 
Washing Water Rubbing 


pe a See 
Setacyl Direct Blue G Powder 3 2-3 5 
Setacyl Direct Blue R Powder 4-5 + a 
Setacyl Direct Yellow 2G Powder s 5 5 
Setacyl Direct Yellow GR Powder 5 5 
Setacyl Direct Yellow R Powder 4-5 2-3 4 
Setacyl Direct Yellow 2R Powder 5 5 5 
Setacyl Direct Orange G Powder 4 4 3-4 
Setacyl Direct Orange 2R Powder 3-4 3-4 4 
Setacyl Direct Red B Powder 3-4 3 4 
Setacyl Direct Red G Powder 3-4 ' 3-4 4 
Setacyl Direct Scarlet G Powder 3-4 3-4 4 
Setacyl Direct Scarlet 2G Powder 5 5 4 
Setacyl Direct Black B Powder 3-4 2-3 5 
Setacy] Direct Black G Powder 3-4 2-3 5 
Setacyl Direct Black R Powder 3-4 23 5 


Note: In the above table the figure 5 indicates the colors of the highest 
degree of fastness while the lower numbers indicate a lower degree of 
fastness. This is just the reverse of the Colour Index. 


The Cellit Fast Dyes 


The Cellit dyes of Bayer and Company are possibly azo com- 
pounds of an acid character, such as those covered by British 
Patent No. 225,862. As they are in powder form, they have cer- 
tain advantages in handling over the paste products. However, as 
they stain cotton, wool, and true silk to some extent, they are not so 
well suited for contrasting multicolored acetate silk effects on 
unions. They are generally applied to unions by Method No. 95. 
The following dyes are available at present: Cellit Fast Rubine B, 


a 


THE ACID AND MORDANT DYES 181 


Cellit Fast Red B, Cellit Fast Blue R, Cellit Fast Violet 2R, Cellit 
Fast Yellow 2G, 2GN and R, Cellit Fast Brown G, and Cellit Fast 
Orange G. All of these products are of high tinctorial power, but 
the Violet 2R is particularly strong, one per cent giving a deep 
brilliant shade, while as much as five per cent of some of the other 
dyes may be required for deep shades. 

On acetate silk, Cellit Fast Red B, Rubine B, Orange G, Blue 
R, Yellow R and 2GN have a good fastness to washing and are 
about equal to the Diazo Fast types on cotton, usually exceeding 
the Benzo Fast colors. Cellit Fast Violet 2R and Brown 2G are 
not as fast to washing as the others. Their fastness to light is 
usually good as compared with the Benzo Fast colors, but Cellit 
Fast Brown G, Blue R, and Violet 2R are not as good in this 
respect as the others. As a class they do not withstand cross- 
dyeing at the boil, but this is seldom necessary or desirable on ace- 
tate silk. They do not discharge to a clear white with sodium 
formaldehyde sulfoxylate. While they stain the cotton or viscose 
present in unions, this staining may be removed by a soaping, as 
explained under clearing unions. They dye both true silk and wool 
from an acid or neutral dye bath, acetic acid completely exhaust- 
ing the dye bath, and may therefore have a particular usefulness 
for certain solid shades on wool or true silk acetate silk unions. 
Cellit Fast Yellow 2GN, which may be diazotized and developed 
on the fiber, is discussed further under the Developed Colors, 
Chapter XVII. 

Method No. 46: The Cellit Fast Dyes on Acetate Silk. These 
dyes should be applied in about a 25 to 1. dye bath at 60 to 65° C. 
(140 to 150° F.) with an addition of 30 to 50 per cent of sodium 
chloride or anhydrous sulfate. In the case of Cellit Fast Yellow 
RGN, a further addition of 3 to 5 per cent of 30 per cent acetic 
acid is required. Ordinarily they may be combined with each 
other, or with other dyes, for use in dyeing compound shades or 
unions. 

Method No. 47: Alkali Blue on Acetate Silk. Alcaline Blue 
H5B (Alkali Blue) may be applied to acetate silk in a neutral salt 
bath at 60 to 70° C. (140 to 158° F.) for about an hour. The 
fiber should then be rinsed and the color developed at 40 to 60° C. 


182 ACETATE SIE 


(104 to 140° F.) in a formic acid bath. In case acid dyes are 
used with this blue, they may be applied in the acid developing 
bath. 

Method No. 48: Alizarine Red on Lustron for Gold Color. 
Alizarine Red Y and B, 20 per cent pastes, may be applied to 
Lustron to give either gold or purple shades (Method No. 49), 
depending upon how it is applied. For a gold shade, the dye bath 
is prepared with 4 per cent of Alizarine Red Y, 2 per cent of tan- 
nin, 1 per cent of acetic acid and 2 per cent of salt. The material 
is dyed at 80° C. (175° F.) for an hour. If the color is too glary 
it may be dulled or browned somewhat by substituting potessium 
bitartrate (cream of tartar) for the acetic acid above; or the dyed 
material may be after-treated in a cold bath containing a pound 
each of sodium carbonate and soap per 120 gallons of water, 
until the desired brown is obtained. Where this method is used 
in dyeing acetate silk-cotton unions, it may be necessary to clear 
the cotton with dilute acetic acid or a sodium bicarbonate and soap 
treatment, as described in Clearing Unions. 

Method No. 49: Purple on Lustron with Alizarine Red. Use 
2 per cent of Alizarine Red and just sufficient acetic acid to keep 
the dye bath an orange color, and not red, when hot. Dye for one 
hour at about 80° C. (175° F.) and then develop the color at the 
same temperature in a bath containing 5 per cent of Turkey-red 
oil (soda), slightly alkaline with ammonia. This treatment should 
be continued until the acetate silk comes to its final shade, or if 
this shade is obtained rather soon, for at least one-half hour, in 
order that the color shall be fully developed throughout the fiber 
and keep its shade on drying. This Turkey-red oil treatment 
will also usually clear the cotton in acetate silk-cotton unions. 

Method No. 50: Alizarine Violets and Browns on Lustron. 
Alizarine Violet 2BS and Z4B, and Alizarine Browns, such as 
the ZW marks, may be applied to Lustron with a small amount 
of acetic acid, as in Method No. 25. The progress of the dyeing 
can be determined by spotting the goods with a little ammonia as 
the color does not develop in the acid bath. After dyeing, the 
goods should be rinsed and developed with Turkey-red oil and 
ammonia as in Method No. 49. 


THE ACID AND MORDANT DYES 183 


Method No. 51: Alizarine Blue on Lustron. Alizarine Blue S 
(C. I. No. 1067) may be applied to Lustron in a dye bath con- 
taining 2 to 4 per cent of the dyestuff, 1 per cent of acetic acid, 
15 per cent of salt and 6 per cent of 32° Tw. (1.16 sp. gr.) chro- 
mium acetate liquor. Dye at not over 65° C. (150° F.) for an 
hour, rinse and steam for one hour without pressure. The color 
may be brightened by topping it with a mixture of Crystal Violet 
and Victoria Green in a neutral bath, which may be heated to aid 
the exhaustion. In using this method on acetate silk-cotton unions, 
the cotton should be cleared with sodium bicarbonate and soap, 
before the topping operation. 

Method No. 52: Anthracene Blue on Lustron. Anthracene 
Blue can be applied as an acid dye with acetic acid and salt, as in 
Method No. 25, or it may be applied with salt alone, in which case 
the shade is bluer and weaker. In the latter case, on unions, it 
gives a lavender shade on the Lustron and a dull blue shade on 
the cotton. The fastness to light is excellent and good to acids, 
alkalies, washing, and rubbing. 

The application of the acid dyes to acetate silk by means of 
ammonium thiocyanate is covered by Method No. 31, Chapter X. 


References 


1A. J. Hall and M. I. Aische, J. Textile Inst. 17, 104-10T (1926). 
2W. E. Sanderson, J. Soc. Dyers and Colourists 38, 162-5 (1922). 
SA. J. Hall, Textile Colorist 46, 153-7 (1924). 

*G. Emmons, American Dyestuff Reporter 10, 268 (1922). 

5J. F. Briggs, J. Soc. Dyers and Colourists 37, 287-96 (1921). 


CHARTER 


THE PATENTS COVERING THE PREPARATION AND 
APPLICATION OF DYES OF THE ACID AD i 
DANT TYPE TO ACETATE Sis 


In any discussion of the patents covering the preparation and 
application of dyes for and to acetate silk, it is frequently almost 
impossible to positively classify the patent from the information 
available. Very often products which from the patent appear to 
be of the acid or mordant type, are applied by the dispersol method. 
In fact, without doubt many of the products covered in the follow- 
ing patents may be applied by either direct or the dispersol meth- 
ods, which latter, after all, is really a direct method also, only that 
generally the dyestuffs used in the dispersol method are not very 
highly soluble in water and are therefore solubilized. in the dye 
bath by a special method which will be discussed later. Also some 


of the products covered by these patents resemble vat dyes but are 


probably not applied by the alkaline hydrosulfite method. In some 
cases, patents given in connection with the dispersol dyes, Chapter 
XXIII, may belong in the present chapter. Many of the new acid 
and mordant dyes also have some uses upon fibers other than 
acetate silk, such as wool, or true silk. 

One of the first patents covering the application of acid as well 
as other dyes to acetate silk is British Patent No. 158,340 and 
United States Patent No. 1,398,357, previously mentioned in 
Chapter X in connection with the use of ammonium thiocyanate 
in dyeing. 

British Patent No. 190,313, October 29, 1921, to W. Harrison 
and Burgess, Ledward & Company, covers the use of dyestuffs 
containing an azo group associated with one or more alkylamino 
groups, but not containing sulfonic or carboxylic groups directly 
attached to the carbon atoms in the benzene nuclei. Suitable 
dyes are those prepared by coupling methylaniline or dimethyl- 
aniline with the diazo compounds of aniline, chloroanilines, nitro- 


184 


T= 


Pret ake tiION, APPLICATION OF DYES 185 


anilines, nitroanisidine, aminomethylanilines, aminodimethylani- 
line, naphthylamines or aminoazobenzenes, or with the tetrazo 
compounds of benzidine, dianisidine, or diaminodiphenylmethane. 
Such dyes are usually soluble in formic, acetic, or sulfuric acid, 
and may be mixed with water and a protective colloid. They are 
usually applied at 70 to 80° C. (158 to 176° F.) to give yellow, 
orange, or red shades. A provisional specification states that 
aminoazo compounds or arylaminoazo compounds, such as amino- 
azotoluene, aminoazonaphthalenes, aminoazonaphthols, or amino- 
azonaphthylamines, may also be used. 

British Patent No. 202,157, July 29, 1922, to the British Dye- 
stuffs Corporation, E. B. Anderson, J. Baddiley, and J. Hall; and 
United States Patent No. 1,498,315, June 17, 1924, to the last 
two inventors above, cover carboxylated azo dyes. ‘These patents 
state that acetate silk may be dyed directly by means of aminoazo 
or aminoazo substituted dyes, solubilized by means of one or more 
carboxyl groups, in place of the usual sulfonic group or groups. 
These dyes may contain diazotizable amino groups, so that dif- 
ferent shades may be obtained by diazotization and development 
on the fiber with the usual components, such as the naphthols, 
phenols, etc. The dyes are applied directly as their sodium salts 
in an aqueous dye bath, either alone or with sodium chloride, sul- 
fate, or a dilute acid, to assist exhaustion. The resulting shades 
are similar to those of the corresponding Ionamines. 

The following examples of acetate silk dyes are given with the 
colors obtained directly and by diazotization and development: 
When m-aminobenzoic acid with o-anisidine is dyed directly, a 
yellow color is obtained, which upon development with B-hydroxy- 
naphthoic acid gives a magenta red color; or with p-aminodi- 
phenylamine, a golden yellow color. m-Aminobenzoic acid with 
anthranilic acid gives a direct yellow color which with B-naphthol 
develops a red; with B-hydroxynaphthoic acid, a bluish-red; or 
with p-aminodiphenylamine, an olive color. p-Aminosalicylic acid 
with a-naphthylamine also gives a direct yellow, which with B- 
naphthol gives a violet ; B-hydroxynaphthoic acid, a reddish-blue ; 
or with p-aminodiphenylamine, an olive color. 

5-Acetylamino-2-amino-4-methoxytoluene with B-hydroxynaph- 


186 ACE VAT Ws hiss 


thoic acid gives a direct bluish-violet color, which, upon diazotiza- 
tion and development with B-naphthol, gives a greenish-blue; with 
B-hydroxynaphthoic acid, a blue; or with p-aminodiphenylamine a 
reddish-violet color. m-Aminobenzoic acid with p-xylidine and 
m-phenylenediamine gives a direct red shade which may be de- 
veloped with B-naphthol or B-hydroxynaphthoic acid to a reddish- 
brown, or with p-aminodiphenylamine to give a brown color. m- 
Aminobenzoic acid with -xylidine and a-naphthylamine, when 
dyed directly gives a brownish-red, which, upon development with 
B-naphthol, is a reddish-violet; or with p-aminodiphenylamine, 
a brown color. m-Aminobenzoic acid with m-toluidene gives a 
direct yellow shade, and when developed with B-naphthol, a scar- 
let; or with B-hydroxynaphthoic acid a bluish-red color. 

Anthranilic acid with anisidine dyes gives a direct orange, which 
changes to a bluish-red upon development with B-naphthol; or 
with B-hydroxynaphthoic, a reddish-blue color. m-Aminobenzoic 
acid with a-naphthylamine dyes a direct reddish-orange, which 
develops to a reddish-violet with B-hydroxynaphthoic acid. p- 
Aminobenzoic acid with aminohydroquinonedimethyl ether dyes 
acetate silk an orange color which develops reddish-violet with 
B-naphthol; or a blue, with B-hydroxynaphthoic acid. m-Amino- 
benzoic acid with 4-nitro-2-anisidine dyes a direct greenish-yellow, 
which with B-naphthol develops a reddish-orange; or with B- 
hydroxynaphthoic acid, a red color. m-Aminobenzoic acid with 
1, 2-aminonaphthol ether dyes a direct red, which develops a 
greenish-blue with B-naphthol ; or a bluish-green with B-hydroxy- 
naphthoic acid. 

British Patent No. 204,280, April 5, 1923, to the Badische Ani- 
lin und Soda-Fabrik, and United States Patent No. 1,526,142, Feb. 
10, 1924, to F. Gunther, assignor to Badische, may cover the 
“Extra Pastes for Acetate Silk.” This patent covers the dyeing 
of acetate silk by means of the bisulfite compounds of compara- 
tively insoluble azo dyes. It states that a soluble dye may be 
prepared by coupling the base with a suitable developer and then 
combining the insoluble azo compound with bisulfite to form a 
soluble compound. For example, a dye bath may be prepared 
with 3 to 5 per cent of the bisulfite compound of benzeneazo-B- 


Phare tlON, APPLICATION OF DYES 187 


naphthol and 1 per cent of 100 per cent acetic acid. The previously 
thoroughly wet-out acetate silk is entered at about 50 to 60° C. 
(122 to 140° F.) and worked for some time. The temperature 
of the bath is then gradually raised to 70 or 75° C. (158 or 167° 
F’.), and the material subsequently rinsed. Also see the patents 
covering the Ionamines, Chapter XX. 

According to British Patent No. 220,308, August 1, 1924, to 
the Society of Chemical Industry of Basle, and United States 
Patent No. 1,534,506, April 21, 1925, to G. de Montmollin and G. 
Bonhote, assigned to the above company, both of which appear to 
cover the same process, azo acid dyes which give yellow to bluish- 
red or brown shades on acetate silk, may be prepared by coupling 
unsulfonated nitrodiazo compounds of the benzene series, except 
those having a hydroxy group ortho to the diazo group, with mono- 
sulfonated monoamines of the benzene series, not derived from 
metanilic or m-toluidine sulfonic acids, and substituted at the nitro- 
gen atom by a residue containing a benzene nucleus. These dye- 
stuffs have the general formula NR:NX YZ, in which R represents 
a non-hydroxylated benzene nucleus carrying at least one nitro 
group; X, a benzene nucleus not having any sulfonic acid group at- 
tached in the ortho position to the azo group; Y, a residue con- 
taining a benzene nucleus; and Z, hydrogen or alkyl; and in which 
only one of R, X, or Y contains one sulfonic acid group. 

For example, 183 parts of 2,4-dinitroaniline are diazotized with 
the calculated quantity of nitrosyl sulfate in concentrated sulfuric 
acid, and the mixture poured on ice. The product is added, while 
stirring, to a solution of 313 parts of the sodium salt of N-ethyl- 
N-p-sulfobenzylaniline. The dyestuff separates rapidly, is filtered 
off and dried to a bronze powder, which gives bluish-red shades 
on acetate silk from an acetic acid dye bath. The product from 
diazetized 2,6-dichloro-4-nitroaniline and diphenylaminesulfonic 
acid, gives an orange tint; while that from m-nitroaniline and 
benzylanilinesulfonic acid gives yellow shades. These dyes are 
applied from a slightly acid or neucral dye bath to give shades of 
good fastness to washing and very good fastness to light. 

According to British Patent No. 224,363, October 25, 1923, to 
the British Dyestuffs Corporation, Baddiley and Tatum, anthra- 


188 ACETAL Ee Stizie 


quinone dyes, which are very soluble in water, dilute acids, and 
alkalies may be prepared from a suitable aminoanthraquinone by 
condensation with an alkylene oxide carboxylic acid in glacial acetic 
acid, with or without a catalyst, such as copper. For example, 
10 parts of 1,4-diaminoanthraquinone are suspended in 100 parts 
of glacial acetic acid and 0.5 part of copper acetate. Twenty parts 
of methylglycidic acid are added; and after stirring for two days 
at room temperature, the whole is poured into 2000 parts of water, 
the solution neutralized with sodium hydroxide, 100 parts of salt 
added, and filtered. The dyestuff is salted out from the filtrate 
and forms a blue powder on drying. The product dyes wool very 
bright shades of good general fastness, as well as dyeing acetate 
silk. The dyes obtained from methylglycidic acid or the potassium 
salt of phenylglycidic acid and 1,4-diaminoanthraquinone give blue 
shades; while the latter acid gives a red dye with a-aminoanthra- 
quinone; or, a purple dye with a-amino-4-hydroxyanthraquinone. 

Very probably the Cellit dyes are covered by British Patent No. 
225,862, December 5, 1923, to F. Bayer and Company. This 
process covers the production of azo dyes by coupling diazotized 
dinitroanilinesulfonic or carboxylic acid with an aromatic amine, 
which does not contain a sulfonic group, but which may be substi- 
tuted in the amino group. For instance, a deep red color may be 
obtained on acetate silk with the product obtained by diazotizing 
280 parts of the ammonium salt of 2,6-dinitroaniline-4-sulfonic 
acid and coupling with 143 parts of B-naphthylamine in acid solu- 
tion. The 2,6-dinitroaniline-4-sulfonic acid may also be coupled 
with a-naphthylamine or ethyl-a-naphthylamine. Other suitable 
dyes are obtained by coupling 2,4-dinitroaniline-6-sulfonic acid 
with ethyl-B-naphthylamine; or 2,4-dinitroaniline-6-carboxylic 
acid with ethyl-B-naphthylamine. These latter products. dye ace- 
tate silk bordeaux, violet, blue, and bluish-violet shades, respec- 
tively. Also see German Patent No. 423,601. 

British Patent No. 226,948, November 30, 19238, to the British 
Dyestuffs Corporation and G. H. Frank, covers the use of mono- 
sulfonated azo dyes which do not contain hydroxy groups, and 
have this sulfonate group in the ortho position to an azo group. 
Monoazo dyestuffs prepared by combining an unsulfonated diazo 


v ET 


ee ee ee ee SS ee 


Peete LION, APPLICATION OF DYES 189 


compound, containing no hydroxy groups, with naphthylamino-8- 
sulfonic acid or its phenyl or other derivatives, also have an 
affinity for acetate silk. A hydroxyl group is capable of increasing 
the activity of the sulfo group to such an extent as to diminish the 
affinity of the dye for acetate silk. 

In this manner acetate silk dyes may be obtained by coupling 
diazotized 2,1-naphthylaminosulfonic acid with N-alkyl or N-aryl 
substituted amines, particularly substituted naphthylamines, or 
with m-toluylenediamine. For instance, the products from diazo- 
tized p-nitroaniline-o-sulfonic acid combined with phenyl-a-naph- 
thylamine (brown), /-tolyl-a-naphthylamine (brown), ethyl-a- 
naphthylamine (violet), ethyl-B-naphthylamine (violet), phenyl- 
B-naphthylamine (violet), a-a’-dinaphthylamine (brown), or 
B-B’-dinaphthylamine (bluish-violet), have a high affinity for ace- 
tate silk. By the reduction of the nitro group and coupling with a 
m-diamine, other valuable dyes are obtained. Other acetate silk 
dyes mentioned which contain sulfo groups in the peri position to 
the amino or substituted amino group, are p-nitroanilineazo-1, 
8-naphthylaminesulfonic acid (peri acid) and p-nitroanilineazo- 
phenyl-peri acid. These dyes are applied to acetate silk from 
slightly alkaline dye baths. Also see United States Patent No. 
1,534,506. 

According to British Patent No. 228,557, January 29, 1924, to 
Meister, Lucius and Bruning, acetate silk may be dyed deep violet 
to blue shades of good fastness to washing and excellent fastness 
to light by monosulfonated 1, 4-diaminoanthraquinone or 1, 4- 
aminohydroxyanthraquinone, or an alkyl, aralkyl or aryl deriva- 
tive of these compounds having the sulfo group in the 2- or 3- 
position. The dye bath may also contain salts, acids, or protective 
colloids. United States Patent No. 1,587,669, June 8, 1926, to C. 
E. Muller, assigned to the Grasselli Dyestuff Corporation, covers 
the same process. 

British Patent No. 230,055 of 1925, a modification of patent No. 
225,862, states that a blue dye for wool may be obtained by coup- 
ling diazotized dinitroanilinesulfonic or carboxylic acid with the 
sulfonic or carboxylic acid of B-naphthylamine or its derivatives. 


190 ACETATE Siig 


British Patent No. 232,599, April 15, 1925, to Meister, Lucius 
and Bruning states that the glycines, obtained by the action of 
the halogen-acetic acids on nonsulfonated aromatic bases, in- 
cluding basic dyestuffs containing a free amino group, and par- 
ticularly their water-soluble salts, are suitable for dyeing acetate 
silk by direct absorption. Acids, salts, or protective colloids may 
be added to the dye bath and the compounds may be diazotized on 
the fiber, and developed with an amine, phenol, or aminophenol. 
For example, a kilogram of acetate silk is dyed a fast violet shade 
by immersion for an hour at 60 to 70° C. (140 to 158° F.) ina 
20 or 25 to 1 dye bath containing 20 grams of the glycine formed 
from 1,4-diaminoanthraquinone. Yellow, deep blue and reddish- 
violet shades are obtained by using the glycines formed from 
aminoazobenzene, 1,4,5,8-tetraaminoanthraquinone, and 1-amino- 
4-hydroxyanthraquinone respectively. A  violet-black color of 
good general fastness properties is obtained by dyeing acetate 
silk with the glycine of a-naphthylamine, subsequently diazotizing 
on the fiber and coupling with B-hydroxynaphthoic acid. 

British Patent No. 243,737, November 25, 1924, to Meister, 
Lucius, and Bruning, states that the slightly basic monoazo dye- 
stuffs containing a sulfamino group in the diazo component are 
particularly suitable for dyeing acetate silk and other cellulose 
esters and ethers in deep, fast colors. For example, 1000 grams 
of acetate silk can be dyed in a 20 to 25 liter bath containing 30 
grams of the dyestuff from diazotized 4-aminobenzene-1-sulfa- 
mide and aminocresol ether. The temperature is gradually raised 
to 70° C. (158° F.), maintained for a half hour, 200 grams of 
ammonium acetate are added and the dyeing continued at 70° C. 
for a further half hour. After rinsing, a vivid golden yellow color 
of excellent fastness is obtained. Diazotized 2-nitro-1-aminoben- 
zene-4-sulfamide with m-toluidine gives an intense orange; and 
diazotized 4-aminobenzene-1-sulfamide with a-naphthylamine 
gives a deep reddish-orange. British Patent No. 243,738 is prob- 
ably along the same line. : 

British Patent No. 244,267 of 1924, to the British Dyestuffs 
Corporation, W. H. Perkin and C. Hollins appears to cover a 
new variety of acetate silk direct dyestuffs. This patent states that 


Pore LION, APPLICATION OF DYES LoL 


acetate silk may be dyed various shades directly by derivatives of 
amino-, diamino-, or polyamino-anthraquinones or their substitu- 
tion products, excluding sulfonated derivatives obtained by com- 
plete acvlation followed by nitration. The products may be hydro- 
lyzed and reduced if desired. Other nonaromatic acyl groups may 
be introduced instead of the acyl groups, but it is found that ben- 
zoylation destroys the affinity for acetate silk. It is unnecessary 
to use a dispersing agent such as that referred to in British Patent 
No. 224,077 or other dispersing agents, such as Turkey-red oil. 
For example, 20 kilograms of diacetyl-1, 8-diaminoanthraquinone 
are dissolved in 100 kilograms of concentrated sulfuric acid and 
mononitrated at 5 to 10° C. with 48 liters of mixed acid, contain- 
ing 200 grams of nitric acid per liter, for an hour. The product is 
precipitated by pouring into water, and may be crystallized from 
chlorobenzene. It gives a rich brown shade on acetate silk directly. 

British Patent No. 245,758, January 6, 1925, to the Chemische 
Fabrik vorm. Sandoz covers the production of cellulose ester 
dyes, suitable for use on acetate silk, containing one or more glycol 
ether or glycerol ether groups in the aryl nuclei, but no sulfonic 
or carboxylic groups. They may be prepared by coupling diaz- 
otized aminoarylglycol ethers or aminoarylglycerol ethers with 
the usual components. | 

In British Patent No. 245,790, to the I. G. Farbenindustrie, the 
dyeing of cellulose esters and ethers with monoazo dyes contain- 
ing as a coupling component an o-aminophenol ether or a mono- 
acyl-m-phenylenediamine or a homologue or substitute thereof, is 
covered. The dyeings may be diazotized and developed. Examples 
are given for obtaining a deep yellow, an orange, and yellow to 
orange tints on acetate silk. 

British Patent No. 248,858, December 16, 1924, to the British 
Dyestuffs Corporation, W. H. Perkin and C. Hollins, covers new 
carbamides of the anthraquinone series containing 2 or 3 anthra- 
quinonyl groups linked together by the chain -NH.CO.NH-, which 
have an affinity for acetate silk. These are obtained by condens- 
ing a-anthraquinonylethyl carbamate or a-anthraquinonylcarbamic 
chloride with equimolecular proportions of a-aminoanthraquinones 
or derivatives, preferably those having two amino groups ‘in the 


192 ACETATE Silus 


a-positions, such as 1,4-, 1,5-, 1,8-diaminoanthraquinones, diamino- 
anthrarufin or diaminochrysazine. For example, 13.5 kilograms 
of diaminoanthrarufin when heated with 14.5 kilograms of a-an- 


thraquinonylethyl carbamate (or an equivalent porportion of the 


corresponding carbamic chloride) at the melting point of the mix- 
ture for about a half-hour, form a product which dyes acetate silk 
a brown shade and is probably a monocarbamide. Diaminochrysa- 
zin and a-anthraquinonylethyl carbamate condensed in the same 
way give a product which is probably the dicarbamide and which 
dyes acetate silk a steel-gray shade. These products may possibly 
be applied by a dispersol method. 

British Patent No. 252,240, November 25, 1924, to C. M. Bar- 
nard and the British Alizarine Company states that acetate silk and 
other cellulose esters may be dyed with compounds having the 
general formula A.N.(Y.CO2H)Ri or A.N.(Y.CO2H)Z.COeH, 
in which A is an unsulfonated aryl dye nucleus, N is an atom of 
nitrogen, R; is an atom of hydrogen or an alkyl or other substituent, 
and Y and Z are the same or different aliphatic chains which may 
be branched or straight, substituted or unsubstituted. The nonsul- 
fonated aryl dye nucleus may be any of the well-known groupings 


such as anthraquinone’or its derivatives, azo compounds, indigo or 


its derivatives, but it is preferable to maintain the molecular weight 
as low as possible. One group of especially suitable compounds 
of this type is formed by the condensation of a molecule of amino- 
or imino-derivative of an unsulfonated aryl dye nucleus with at 
least one molecule of an aliphatic polycarboxylic acid. Two gen- 
eral methods for preparing suitable substituted glycine dyes are 
(a) treatment of one molecule of an aromatic amine in a suitable 
solvent with one molecule of an aldehyde, one molecule of sodium 


bisulfite, and one molecule of potassium cyanide, and subsequent — 


hydrolysis with boiling sodium hydroxide or sulfuric acid of the 
nitrile thereby formed. (b) Condensation of an aromatic amine 
with a halogenated aliphatic acid other than halogenated acetic 
acid. The anthraquinone derivatives of this type give very bright 
and fast shades, chiefly orange and red. Thus, the condensation 
product of 1-aminoanthraquinone and B-chloropropionic acid, dyes 
red. The compounds prepared by fusing o-carboxyphenylamino- 


PoerArATION, APPLICATION OF DYES 193 


diacetic acid with potassium hydroxide and oxidation of the leuco 
compound, dyes blue. 

British Patent No. 252,646, November 15, 1924, and July 4, 
1925, to Barnard and the British Alizarine Company states that 
acetate silk and other cellulose esters may be dyed by azo and 
anthraquinone compounds having the general formula A.X.Y. 
CO2H, in which A is a nonsulfonated aryl dye nucleus, X is an 
atom of oxygen or sulfur, and Y is a straight or branched sub- 
stituted or unsubstituted aliphatic chain. It is desirable that A 
has a low molecular weight but either azo or anthraquinone com- 
pounds are suitable. One group of such dyes consists of deriva- 
tives of glycollic or thioglycollic acid or homolgues of these acids 
in which a hydrogen atom attached to the oxygen or sulfur atom 
is replaced by an unsulfonated aryl dye nucleus. Suitable com- 
pounds are: (1) the azo dye prepared by condensing p-nitrophenol 
with chloroacetic acid, then reducing the nitro group to an amino 
group, and afterwards diazotizing and coupling with B-naphthol. 
(2) Anthraquinone and its derivatives are especially suitable as 
the aryl nuclei to be linked with the oxygen atom. (3) 1-Amino- 
anthraquinone-2-thioglycollic acid obtained by treating 1-amino-2- 
mercaptoanthraquinone with sodium hydroxide and glucose at 70° 
C. (158° F.) and adding chloroacetic acid, dyes orange-yellow. 
(4) By boiling 1-amino-2, 4-dibromoanthraquinone with sodium 
sulfide and then condensing with chloroacetic acid a dyestuff is 
obtained which dyes a bright bluish-red color. (5) 1- and 2-amino- 
anthraquinonethioglycollic acids are yellow dyes. 

In British Patent No. 253,457, June 29, 1925, W. Carpmael for 
the Bayer Company, states that monoazo dyestuffs giving pure, 
even shades on wool are obtained by coupling diazotized amines 
or their substitution products with omega-aminoalkyl-B-naphthyl- 
amines or their derivatives prepared as in United States Patent 
No. 1,543,569, and British Patents No. 230, 457 and No. 249,717. 
These products also give good dyeings on acetate silk when they 
contain only one sulfonic or carboxylic group, which must be 
present in the diazo component. Thus, the dye from 2,4-dinitro- 
aniline-6-sulfonic acid and omega-aminoethyl-B-naphthylamine on 
treatment with acetic anhydride at 65 to 75° C. (149 to 167° F.) 


194 ACETATE Slit 


gives a product dyeing acetate silk a blue color and wool a green- 
ish-blue color, 4-Nitroaniline-2-sulfonic acid and the monoacyl 
derivative of omega-aminoethyl-B-naphthylamine give a product 
dyeing acetate silk a reddish-violet and wool a violet color. 5-Nitro- 
2-aminobenzoic acid and omega-aminoethyl-B-naphthylamine give 
crystalline products dyeing acetate silk bluish-pink. Many other 
products are mentioned. 

British Patent No. 257,654, May 29, 1925, to the British Dye- 
stuffs Corporation, R. S. Horsfall, L. G. Lawrie, J. A..R. Hen- 
derson and J. Hill states that water soluble dyes which may be 
used for dyeing acetate silk, without the use of solubilizing or dis- 
persing agents, are obtained from many acid and direct dyes by 
converting their sulfonic acid groups into sulfoamide groups by 
successive treatment with phosphorous pentachloride and am- 
monia. Or, alternatively, by the synthesis of dyes of the acid 
type from coupling components already containing the sulfon- 
amide groups. In this manner a reddish-orange color is obtained 
by using the dyestuff prepared by combining diazobenzene with 
1-naphthol-3, 8-disulfonamide (1 per cent), together with 1 to 2 
per cent of formic or sulfuric acid at 74 to 77° C. (165 to 2vis 
F.) for a half hour. Orange shades are obtained by using in a 
similar way the dyestuff prepared by coupling diazobenzene with 
1,8-naphthasaltam. No dispersing agents are necessary in the 
application of these dyestuffs. 

German Patent No. 420,017, June 12, 1923, to F. Gunther and 
F. Lange, assignors to the Badische Company, states that cellulose 
esters may be dyed with water soluble sulfamic acids of the dye- 
stuff, and the colors obtained may be diazotized and developed with 
chromogens, or coupled with diazo compounds. Thus, the azo 
dye from p-aminophenylsulfamic acid and B-naphthol, used in 
acid solution, gives brownish-red shades, while further diazotiza- 
tion and treatment with B-naphthol produces a red-violet color. 

German Patent No. 423,601, December 25, 1923, an addition to 
No. 418,490 (See British Patent No. 225,862), to the Bayer Com- 
pany, assignees of W. Duisberg, W. Hentrich, and L. Zeh states 
that azo dyestuffs suitable for dyeing acetate silk are prepared by 
coupling diazotized amines or their substituted derivatives with 


Peer eakhATION, APPLICATION OF DYES 195 


aralkylarylamines or their substituted derivatives containing car- 
boxylic or sulfonic acid groups. For example, yellow, bordeaux, 
and orange-red dyes are obtained by coupling 5-nitro-2-anisidine 
and benzyl-o-sulfanilic acid, 2,4-dinitroaniline and 4-sulfobenzyl-2- 
toluidine, and 2,4-dinitroaniline and benzylanthranilic acid, respec- 
tively. Also see United States Patent No. 1,595,178. 

United States Patent No. 1,574,748, March 2, 1926, to J. Bad- 
diley and W. W. Tatum covers dyes of the general formula 
A.NH.SOz.(1)CgH3.- COOH (3).OH(4), in which A represents 
an anthraquinone residue which may be substituted. As acid dyes 
they are directly applicable to wool, with or without a chrome 
mordant. They may also be applied to acetate silk. Among the 
starting materials used in their preparation are diaminoanthrarufin, 
or 1,4-diaminoanthraquinone, or 1,4,5,8-tetraaminoanthraquinone 
and salicylic sulfochloride. Very possibly these dyes are applied 
to acetate silk by the dispersol method. See British Patent No. 
BU Ty 1s 

United States Patent No. 1,575,324, March 2, 1926, to W. Duis- 
berg W. Hentrich, covers acetate silk dyes of the type R.N:N.R’, 
in which R.N:N- stands for the diazo derivatives of an acid- 
substituted aromatic nitro compound and R for an aromatic di- 
amine. For example, sodium 4-nitro-1-benzoate-2-azomethylben- 
zylaniline gives clear orange shades on acetate silk. 

According to United States Patent No. 1,587,708, June 8, 1926, 
to W. Duisberg, W. Hentrich, C. Weinand, and L. Zeh, acetate 
silk and similar esters and ethers may be dyed with o-aminoanthra- 
quinonesulfonic acid compounds, such as 1-aminoanthraquinone- 
2-sulfonic acid (orange), 2-aminoanthraquinone-1-sulfonic acid 
(yellow), 2-aminoanthraquinone-3-sulfonic acid (yellow), 1-am- 
ino-4-bromoanthraquinone-2-sulfonic acid (yellowish-red), 1-am- 
ino-5-toluinoanthraquinone-2-sulfonic acid (dark red), 1-amino-4- 
thiotolyanthraquinone-2-sulfonic acid (reddish-violet), and 1-am- 
ino-4-dihydroglyoxalylanthraquinone-2-sulfonic acid (violet). 

United States Patent No. 1,595,178, August 10, 1926, to Duis- 
berg, Hentrich and Zeh states that ammonium 2,6-dinitroaniline- 
4-sulfonate or other acid substituted dinitroanilines can be diazo- 
tized and the resulting diazo compounds coupled with B-naphthyl- 


BT ACETATE SILK 


amine or other aromatic amines having no acid group in the mole- 
cule, to form dyestuffs suitable for dyeing acetate silk and the 
related esters and ethers. See German Patent No. 423,601. 

In United States Patent No. 1,599,748, September 14, 1926, to 
Heinz Eichwede and Erich Fischer, assigned to the Grassilli Dye- 
stuffs Corporation, it is stated that diethylanilinesulfonic acid and 
its substitution products, when coupled with unsulfonated aro- 
matic diazo compounds of the benzene or naphthalene series con- 
taining at least one nitro group, yield dyestuffs which give deep 
shades of good fastness varying from yellow to violet on acetate 
silk and the related esters and ethers. For example: One kilogram 
of acetate silk is dyed a deep golden-yellow shade of good fastness 
by working for 45 to 60 minutes at 60 to 70° C. (140 to 158° is) 
in a 20 or 25 liter dye bath containing 20 grams of the dyestuff 
prepared from diazotized 3-nitro-2-methyl-1-aminobenzene and di- 
ethylaniline-m-sulfonic acid, with or without the addition of a salt 
or an acid, or/and a protective colloid. If the 3-nitro-2-methyl-1- 
aminobenzene of the above example is replaced with 4-chloro-2- 
nitro-1-aminobenzene or 4-nitro-2-aminobenzene-1-carboxylic acid 
ester, or a similar base, deep orange shades of equally good fast- 
ness are obtained. The dyestuff obtained from 2,4-dinitro-1-amino- 
benzene and diethylaniline-m-sulfonic acid gives deep reddish- 
violet shades. This may cover some Cellit dyes. 

In United States Patent No. 1,602,695, October 12, 1926, to R. 
Metzger, assigned to the I. G. Farbenindustrie Aktiengesellschaft, 
claim is made for the use of water-soluble sulfonic acids derived — 
from colored amino compounds which are not dyestuffs in the 
usual sense, especially from aminoanthraquinones, as suitable for 
use in the dyeing and printing of the cellulose esters, including 
acetate silk. These sulfonic (sulfamic) acids may be used as 
such, or in the form of salts, and may contain one or several sul- 
famic (NH—SO3H) residues with or without further substituents 
in their molecules. The dyeing process may be carried out in the 
usual manner, without any preliminary treatment of the acetate 
silk. In many cases the dyeings so obtained may be subjected to 
an after-treatment with diazo compounds or they may be dia- 
zotized and coupled with a suitable component, by which after- 


PREPARATION, APPLICATION OF DYES 19% 


treatments valuable new shades are obtained. Printing is carried 
out in the usual manner. 

For example, the acetate silk may be entered into a ieee 
dye bath containing 3 per cent, on the weight of the goods, of the 
sulfonic acid sodium salt derived from 1,4-diaminoanthraquinone 
(30 per cent purity), 10 per cent of Glauber’s salt, and 4 per cent 
of sulfuric acid. The temperature is slowly raised to 70 or 80° 
C. (158 or 176° F.) until a reddish-violet color is obtained. A 
somewhat lighter shade is obtained on substituting formic acid for 
the sulfuric acid. A redish-blue color is obtained in the same 
manner at about 75° C. (167° F.) with 3 per cent of the sodium 
salt of 1,5-disulfamic-acid-4, 8-dihydroxyanthraquinone (54 per 
cent purity), adding 10 per cent of sodium bisulfate in one or 
several portions. 

_ The acetate silk may be printed in bright bluish-red colors with 
a paste containing 50 parts of the sulfamic acid sodium salt de- 
rived from 1-amino-4-methoxyanthraquinone (43 per cent purity) 
dissolved in 50 parts of glycerol and made into a paste with 900 
parts of thickening. The printed material is dried, steamed, and 
rinsed. 


The “Sulfato” Dyes—Their Preparation, Patents, and Application 
to Acetate Silk 


The application of an entirely new class of dyestuffs to acetate 
silk is covered by British Patent No. 237,739, August 22, 1924, to 
the British Dyestuffs Corporation, W. H. Perkin and S. C. Bate. 
This patent states that a few of the sulfato dyestuffs,? described 
in British Patent No. 181,750, may be applied to acetate silk from 
neutral, acid, or alkaline dye baths to give a variety of shades of 
good fastness to light and washing. The nitrated monoazo dyes 
of this class appear to give the brightest shades. 

For example, acetate silk may be dyed a bright scarlet by 
immersion for an hour at 60 to 80° C. (140 to 176° F.) in a dye 
bath containing 3 per cent of salt, 1 per cent of sulfuric acid and 
1 per cent of the dyestuff obtained by coupling diazotized p-nitro- 
aniline with sodium sulfatoethylaniline. Sulfato dyestuffs con- 


"A, - Green and K. H. Saunders, J. Soc. Dyers and Colourist 39, 39-42 
1923). 


198 ACETATE SILK 


taining amino groups, such as p-aminobenzeneazo-p-sulfatoethyl- 
aniline, may be used and the resulting shades subsequently diazo- 
tized and developed by the usual methods. Two-color effects on 
union materials containing cotton and acetate silk are obtained by 
dyeing in one bath with sulfato dyestuffs having an affinity for 
either, but not both of the fibers. 

Sulfato compounds suitable for dyeing acetate silk are obtained 
by coupling m-nitroaniline with sulfatoethylaniline (reddish- 
yellow), or ethylsulfatoethylaniline (yellowish-orange) ; p-nitro- 
aniline with sulfatoethylaniline (reddish-orange), or sufatoethyl-o- 
toluidine (bright red), or ethylsulfatoethylaniline (scarlet), or 
sulfatoethyl-B-naphthylamine (bright pink), or sulfatoethyl-a 
naphthylamine (magenta) ; 1-nitro-2-naphthylamine with methyl- 
sulfatoethylaniline (orange) ; 4-nitro-1-naphthylamine with ethyl- 
sulfatoethylaniline (brown) ; or 3,5-dinitro-o-toluidine with ethyl- 
sulfatoethylaniline (cardinal red). o-Chloro-p-nitroaniline with 
ethylsulfatoethylaniline (bluish-red), or sulfatoethyl-a-naphthyla- 
mine (bright violet) ; 2,4-dinitroaniline with benzylsulfatoethyl- 
aniline (bluish-red), or sulfatoethyl-a-naphthylamine (navy blue) ; 
and 2,4-dinitro-l-naphthylamine with sulfatoethyl-a-naphthyla- 
mine (greenish-blue). 

The original patent covering these new “sulfato” dyes was 
British Patent No. 181,750 (1922), to the British Dyestuffs Cor- 
poration, A. G. Green and K. H. Saunders, and United States 
Patent No. 1,483,084, February 12, 1924, was based upon the 
discovery that the presence of the alcoholic sulfuric group, 
—C,H,4.SO4H, attached to nitrogen, has a somewhat similar func- 
tion to the sulfonic acid group in dyes. The resulting dye is 
therefore soluble; acid in character, and therefore suitable for 
dyeing real silk and wool. Apart from the fact that these proper- 
ties are characteristic of these new dyes, their use is not restricted 
to the dyeing of animal fibers, as it was originally recognized that 
some of them would dye cotton from a neutral or alkaline dye 
bath, while others may be used in the manufacture of lakes and 
pigments. Members of this group suitable for use as mordant 
dyes were also prepared. Now it has been discovered that certain 
dyes of this class are suitable for acetate silk, so that it may be 


PREPARATION, APPLICATION OF DYES 199 


possible to dye almost any combination of fibers in certain colors 
-with this one class of dyes. 

One or more “sulfato” groups (SO,H), like the sulfonic acid 
group, may be introduced not only into the finished dye, but also 
into one or both components used in the production of the dyestuff. 
The number of sulfato groups which may be introduced depends 
only upon the number of replaceable hydrogen atoms attached to 
nitrogen which are present. British Patent No. 186,878 covers 
the preparation of compounds suitable for sulfation. 

There is also another quite distinctive method which involves the 
use of ethylene chlorhydrin. This is first allowed to react in aque- 
ous or alcoholic solution with a primary or secondary amine or 
diamine of the aromatic or fatty-aromatic series, or one of their 
derivatives, so that an intermediate product containing the hydroxy- 
ethyl residue (—C2H4.OH) is formed. This product is then con- 
verted into a hydroxyethyl dyestuff, which, on subsequent treat- 
ment with concentrated sulfuric acid, yields the required soluble 
dyestuff containing the sulfato group attached to the ethyl residue. 
Thus, if R represents a chromophoric nucleus, the new dyestuffs 
would be represented by R.NH.C2H4.SO4H or R.N(C2H4.SO4 
H)». For example, hydroxyethylaniline, CgH;s.NH.C.H4.OH, ob- 
tained by the action of ethylene chlorydrin upon aniline is readily 
converted by sulfuric acid into phenylaminoethylhydrogen sulfate, 
CeHs.NH.Ce.H4.SO4H, a colorless crystalline solid with acid 
properties which forms easily soluble salts. 

Other chlorhydrins may be used in the same manner, and if 
desired, a sulfonic acid group may be introduced at the same time 
as the sulfato group, however this would possibly not be desirable 
in products for use in dyeing acetate silk. While the above men- 
tions only the sulfatoethyl derivatives, other sulfato-alkyl com- 
pounds may be prepared and used in a similar manner. Thus, by 
reacting with glycerol mono-, di-, or epi-chlorhydrin upon an 
amino compound and treating the product with sulfuric acid, sul- 
fatohydroxypropyl derivatives are obtained, containing for ex- 
ample the group —NH.C3H;(OH).SO4H. These latter dyestuffs 
appear to be less brilliant than the sulfatoethyl derivatives. The 
principal may be applied to almost any class of dyestuffs containing 


200 ACETATE SILK 


nitrogen, for the preparation of “acid” dyes. The various chlor- 
hydrins may be used in the same manner. 

A modification of the foregoing method consists of first form- 
ing B-chlorethylhydrogen sulfate by dissolving ethylene chlor- 
hydrin in concentrated sulfuric acid, 

C.H,CLOH + H.SO,——> C2H4Cl.SO4H + H2O, 

and then allowing this compound to react in a neutral or alkaline 
solution with a dyestuff component, intermediate product, or a dye- 
stuff containing a primary or secondary amino group. In this 
manner the sulfatoethyl group may be introduced by a single 
step; R.NH, ++ CoH,Cl.SO.H ——> R.NH.C,H4SO4H + HCL. 
When ethylenechlorhydrin is used in the preparation of the sulfato 
intermediate product, the general structure of the monoamino 
derivatives in either 


R C.H4.SO,H 
A >N—C.H,.SO.,H or R—N <GH,SO,H, 


in which R indicates an aromatic, or substituted aromatic residue, 
and A represents a hydrogen atom or an alkyl, oxalkyl, aralkyl or 
aryl group. An aromatic diamine may be converted into a mono-, 
di-, tri-, or tetra-sulfato acid. 

To convert the hydroxethyl intermediate compound into its 
sulfato acid, it is only necessary to use sulfuric acid, or a substi- 
tute, of the same concentration as is used in the preparation of 
ethylhydrogen sulfate, the general conditions being the same in 
both cases. The resulting product may be used for the direct prep- 
aration of a sulfato dye. 

Parent basic dyestuffs are prepared from their hydroxyethyl 
components in a manner similar to that used for the corresponding 
dyes from ethyl- and diethylanilines, ethyl-o-toluidine, ethyl-a- 
and B-naphthylamines, dialkyl-m-phenylenediamines, etc. They 
are then treated with sulfuric acid. Both of the foregoing methods 
are applicable to all classes of dyes in which the members can be 
obtained as the corresponding ethyl derivatives. 

In the same manner, sulfato triphenylmethane dyes can be ob- 
tained by condensing a sulfato intermediate with suitable alde- 
hydes, while all types of dyes obtainable from nitroso compounds 
by condensation with amines, phenols, or aminophenols, can be pre- 
pared from nitroso sulfato acids, or a hydroxyethylazine, oxazine, 


Prope LION, APPLICATION OF DYES 201 


or thiazine dye may be converted into its sulfato acid. It is pos- 
sible that prior to this invention sulfato compounds have been 
prepared but not recognized. 

As an example ofthe preparation of these dyes, the sodium salt 
of p-nitrobenzeneazo-p-disulfatodiethylaminobenzene is prepared 
by adding to a solution of 23.1 parts of the sodium salt of disulfa- 
todiethylaniline, a solution containing 10 parts of diazotized p-ni- 
troaniline. Coupling takes place in the presence of acetic acid and 
the dye is salted out. It is a red powder which dyes wool scarlet 
from an acid dye bath and has the formula 

CeHs( NOz).No.CeH4.N (CoHy.SO4Na)s. 

The same dyestuff may be prepared in another manner by dis- 
solving 12.3 parts of dihydroxyethylaniline in dilute acid and 
coupling it with the diazo solution prepared from 10 parts of 
p-nitroaniline. The insoluble red powder is dried, and 1 part is 
heated with 2 or 3 parts of concentrated sulfuric acid at about 30 
to 100° C. until it is soluble in dilute alkali. The melt is then 
diluted and the dye salted out as before. 

The sodium salt of disulfatodiethylditolyphenylcarbinol may be 
prepared by slowly adding 10 parts of the dyestuff obtained ac- 
cording to British Patent No. 13,604 (1914) (by condensing ben- 
zaldehyde with oxethyl-o-toluidine and subsequent oxidation with 
lead oxide) to 20 or 30 parts of cold concentrated sulfuric acid, 
keeping the temperature down. The solution is allowed to stand 
until the product is soluble in alkali. On dilution and salting out, 
a dyestuff is obtained which dyes wool greenish-blue from an acid 
dye bath. The leuco base may be sulfonated before oxidation to 
the carbinol. This dye has the formula 


CeH3 ( CHs) .NH.C.H4.SO,4Na. 
CeHs.C(OH)< C511,(CH;).NH C:H,.SO,Na. 


Sulfatoethylaminodioxytoluphenoxazoniumcarboxylic acid, 
(C2H,SO.Na) . NH . CsH2(CH3 O2>CoH (OH)s COz, 


may be prepared from a dyestuff of the gallocyanine type. This 
gallocyanine dye is prepared by the usual method from p-nitro- 
sooxyethyl-o-toluidine and gallic acid.” Ten parts of this dye are 


>See British Patent No. 182,031 of 1921. 


202 ACETATE (Sik 


added to 20 or 30 parts of concentrated sulfuric acid and the solu- 
tion warmed until it gives no precipitate in a tannin reagent. It is 
then diluted and the dyestuff salted out as a black powder which 
dyes wool a deep blue from an acid dye bath and chrome mor- 
danted wool a violet blue. 

All types of dyestuffs do not yield sulfato compounds with 
equal ease and it has been observed that the finished dyestuff of 
the triarylmethane and quinonimide types, that is compounds 
having the quinonoid structure, are particularly easy to sulfate, so 
that even cold sulfuric acid may be used. Under such conditions 
it is found that solubility in alkali is attained in a few minutes, 
and upon pouring the sulfuric acid solution onto ice, and adding 
salt, the sulfato dyestuff separates and may be collected. On the 
other hand, many leuco bases require to be heated with the acid at 
100° C. for some time to complete the sulfation. The advantages 
of sulfation over sulfonation is particularly apparent with the 
triarylmethane and quinonimide type of dyes which are not easily 
built up from sulfonated intermediates and which are readily 
spoiled by sulfonation with oleum. Sulfation allows any given 
hydroxyalkyl dyestuff with basic properties to be converted into 
an acid dyestuff, while the mild treatment necessary does not 
dull the shade. 

The sulfato dyes have all of the usual characteristics of the 
acid dyes and little difference will be noticed in their application 
and that of the nearest related sulfonated dyestuff. As a class, the 
. sulfato dyes are more level-dyeing than the sulfonated products, 
and the exhaustion of the dye bath is about the same. No hy- 
drolysis appears to occur in the dye bath and the fastness of the 
resulting colors appears to be about the same as that obtained from 
the corresponding sulfonated dye. 

Probably some of these sulfato dyes may find use upon fiber 
combinations containing acetate silk and wool or true silk. As 
they are applied to animal fibers by the usual acid dyeing methods, 
in certain instances the acetate silk may also be dyed a somewhat 
similar shade, the comparison with the shade of the wool depend- 
ing upon the particular dye used and the conditions of application. 
Also see the omega-sulfonic dyes discussed as Ionamines. 


(rat LER LXV 


Preeeeineel COTTON, SULFUR, AND VAT DYES ON 
RoE lTATE SILK 


Thew Preparation, Application and Patents 


Ir is a well-known fact that fully sixty per cent of the direct 
cotton dyes have no affinity for acetate silk. However, as men- 
tioned in Chapter XIII, when applied to acetate silk, the members 
of the acid and mordant classification are applied by the “direct” 
method. While the true dispersol products are usually an en- 
tirely different type of product from any of those mentioned above, 
when they are considered according to their method of applica- 
tion, they too, come under the direct class. However, under 
the above subtitle, we will only consider the dyes of the older 
classification known as the Direct Cotton dyes. Very few of 
these dyes are applicable to acetate silk except by special methods, 
such as saponification, which will be considered later. The 
Setacyl Direct dyes of Geigy and the Cellit dyes of Bayer could 
be classed as Acetate Silk Direct dyes, but they were considered 
under the acid dyes. 

Among the few direct cotton dyes which are applicable to 
acetate silk should be mentioned Pyramidol Brown BG (C.I. No. 
380, the sodium salt of diphenyldisazobisresorcinol), Paramine 
Orange G, Paramine Orange R (C. I. No. 415, the sodium salt 
of diphenyldisazosalicylic-acid-a-naphthylamine-4-sulfonic acid), 
Paramine Yellow 2G (C. I. No. 43, the sodium salt of p-ni- 
trobenzenedisazoaminosulfobenzenylaminothiocresol), and Para- 
mine Brown G (C. I. No. 596, the sodium salt of p-sulfoben- 
zeneazo-m-phenylenediamineazodiphenylazosalicylic acid). Chlora- 
zol Black E extra (C. I. No. 581, the sodium salt of benzen- 
eazo-3,6-disulfo-8 -amino-1-naphthol-7-azodiphenylazo-m-phenyl- 
enediamine) stains Celanese a deep red-gold, undoubtedly due to 
a basic impurity. These dyes may be applied by Method No. 53. 

Method No. 53: Direct Cotton Dyes on Acetate Silk. Start cold 


203 


204 ACETATE SILK 


and raise the temperature at 76° C. (170° F.) in about one-half 
hour. Dye at this temperature for a half-hour and cool one-half 
hour, using 10 to 30 per cent of salt in the dye bath. 

There is a wide variety of direct dyes which do not stain acetate 
silk and a list of these dyes will be found under the dyeing of 
acetate silk-cotton unions, Chapter XX XIII. In selecting direct 
dyes for use upon such unions, where the acetate silk should 
not be stained, care must be taken to obtain direct cotton dyes 
which do not contain either basic impurities or shading compo- 
nents of basic dyes. If this precaution is not taken, various lots 
of the same direct cotton dyestuff may stain the acetate silk in 
different and entirely unexpected shades, much to the consterna- 
tion of the dyer. United States Patent No. 1,398,357 and Brit- 
ish Patent No. 158,340 cover a process of increasing the affinity 
of acetate silk for various dyes, including the direct cotton dyes, 
by means of ammonium thiocyanate. 


The Sulfur Dyes on Acetate Silk 


A few sulfur dyes are probably applicable to acetate silk if ap- 
plied in a hydrosulfite vat in the same manner as the ordinary vat 
dyes to cotton, but giving particular attention to the alkalinity 
and temperature of the dye bath, so as to avoid saponification of 
the acetate silk. They are of course also applicable by the saponi- 
fication process, which will be discussed later in Chapter XIX 
and are used to some extent upon the cotton of acetate silk-cotton 
unions, but by special methods. British Patent No. 179,384, 
Chapter XI, covers their application by precipitation. The sulfur 
dyes may also be printed upon acetate silk in an alkaline paste, 
as will be mentioned under printing, Chapter XXIV. 

Clavel obtained British Patent No. 191,553, Nov. 19, 1921, on 
a process for applying full shades to acetate silk with either sul- 
fur or vat dyes. According to this patent, the dye should be re- 
duced by hydrosulfite in a bath feebly alkaline by ammonia and 
containing only sufficient caustic alkali to combine with the leuco- 
base of the dyestuff, but not enough to hydrolyze the acetate silk. 
Exhaustion of the dye bath is effected by the addition of salts, 
such as the chlorides of calcium, barium, and magnesium, precipita- 


| 


Pree DIKRECT DYES 205 


tion being prevented by the addition of protective colloids, such 
as gelatin, silk boil-off liquor, glucose, starch, etc. 


Vat Dyes on Acetate Silk 


As the vat dyes are usually applied to all fibers from a more or 
less strongly alkaline dye bath or “vat,” they are not particularly 
suited for application to acetate silk; however, certain of the Indi- 
goid vats may be applied to acetate silk with more or less success 
under suitably modified conditions. Since the discovery of the 
dispersol dyes, there is really no reason to apply them to acetate 
silk as many of the products applied by the dispersol method have 
all the good properties of the vat dyes on acetate silk, are easier 
to apply with less chance of injuring the fiber, and give more 
brilliant shades. . 

On account of its greater resistance to alkalies and high temper- 
atures, Lustron is possibly better suited to receive these products 
than some other varieties of this fiber. The “Ciba” vat dyes of 
the Ciba Company have been applied to Celanese, and probably 
certain Helindone, Brilliant Indigo, Thioindigo and Durindone 
brands may.also be applied. 

The fact that vat dyes, by the alkaline hydrosulfite vat method, 
do not follow the same general fastness laws on acetate silk as on 
cotton, and that the later dyes (dispersol) developed especially 
for acetate silk have an even greater fastness upon it than the vat 
dyes, reduces their importance for this fiber very materially. As 
a class the vat dyes on acetate silk all show a tendency to rub off 
badly and their application requires a very careful adjustment of 
alkalinity and hydrosulfite, in order to avoid hydrolysis of the fiber. 

Certain vat dyes, as for instance Indanthrene Bordeaux B, 
Algol Rose R, Algol Scarlet G, Algol Yellow WG, Algol Violet 
B, as well as some of the Anthrene dyes, are absorbed by acetate 
silk from aqueous suspensions, as in the dispersol process, and the 
resulting colors have an excellent fastness. With the present wide 
use of the anthraquinone derivatives by this newer method of 
application, there is possibly not much use for the application of 
the vat dyes to acetate silk by means of the alkaline hydrosul- 
fite vat, except in very special cases, such as upon acetate silk- 
cotton unions. The anthraquinone dyes, when applied by the 


206 ACETATE SILK 


dispersol methods, appear to have all of the fastness properties 
looked for in the vat dyes, and even greater fastness to crocking 
than when applied to acetate silk by the usual vat methods. 
Deeper shades are also usually obtainable by the dispersol methods. 
Certain vat dyes are also applicable to acetate silk by precipita- 
tion methods, as mentioned under British Patent No. 179,384. 

The Lustron Company states that some vat dyes may be ap- 
plied to Lustron, but that the Indanthrene vats usually give only 
pale shades. The alkalinity of the bath should of course be kept 
as low as possible, and by gradually raising the temperature to a 
moderate degree, full vat shades can be put on Lustron with some 
vat dyes. Level shades are only obtained by working the goods 
well while dyeing. This treatment somewhat impairs the water re- 
sistance of Lustron, possibly owing to a partial saponification, but 
they state that it will be twice as strong as the other rayons 
when wet. 

Briggs! states that vat dyes, including the Indigoid and those 
of the Algol and Indanthrene class which can be used without 
caustic soda, are suitable for use in dyeing unsaponified acetate 
silk. Saponification during dyeing is inhibited by the presence of 
an ammonium salt. One of the earliest successful methods of ap- 
plying the vat dyes to acetate silk was developed by the Ciba Com- 
pany for their “Ciba” dyes. Their color card showing these dyes 
on Celanese gives many desirable shades. Method No. 54 gives 
their formula for application. 

Method No. 54: Ciba Vat Dyes on Acetate Silk. The “stock 
vat” is prepared by working one pound of the vat dye in powder 
form, or an equivalent amount of paste, into a smooth paste with 
1.5 pints of 66° Tw. (1.330 sp. gr.) sodium hydroxide solution 
and 3 ounces of Monopole soap. When the dyestuff is used in 
paste form, except in the case of Ciba Orange G paste, the addi- 
tion of Monopole soap can be omitted. This paste is mixed with 
20 gallons of hot water and while stirring well, one pound and 
three ounces of hydrosulfite concentrated is added gradually, and 
the whole allowed to stand for about a half hour. Table XXIX 
gives the equivalent weight of the dyes in powder and paste 
forms, the proper temperature of the stock vat and the color of 
the vat when properly reduced. 


PieeDIREGCE DYES 207 


TABLE XXIX 
TEMPERATURE OF THE STOCK VAT AND CONCENTRATION OF DYESTUFFS 
IN PASTE AND POWDER FORMS 


Tempera- 
ture of 
Parts of — Stock Vat 
Name of Dye Paste Powder Moe Color of Reduced Vat 

Ciba Yellow G 100 10 140 Dull reddish-violet 
Ciba Orange G 100 13.5 122 to 140 ~=Dull brownish-olive 
Ciba Brown R 100 1225 140 Brownish-yellow 
Ciba Scarlet G extra 100 20 104 Bluish-violet 
Ciba Red R 100 10 104 Bluish-violet 
Ciba Red G 100 10 158 Reddish-yellow 
Ciba Pink G 100 10 104 to 122. ~=Dull yellowish-brown 
Ciba Pink B 100 20 140 Reddish-yellow 
Ciba Pink BG 100 10 140 Greenish-yellow 
Ciba Violet B 100 10 158 Dull golden yellow 
Ciba Violet 3B 100 10 158 Golden yellow 
Ciba Blue 2B 100 16 158 Golden yellow 
Ciba Blue 2G 100 16 158 Yellowish-olive 
Ciba Green G 100 10 158 Reddish-orange 
Indigo Ciba R 100 20 122 Golden yellow 


The “dye vat” is prepared by adding three ounces of 30 per cent 
ammonia, one ounce of hydrosulfite concentrated powder, and 
six ounces of fish glue, previously dissolved in water, to each 200 
gallons of bath at 71° C. (160° F.). The dye solution from the 
“stock vat” is then added to the dye vat through a fine sieve or 
cloth. 

The scoured goods, if dry, are wet-out in a bath containing 25 
ounces of olive oil soap and 25 ounces of ammonia, per hundred 
gallons of liquor, at 55 to 60° C. (130 to 140° F.) for one-half 
hour and are then entered into the completed dye vat and dyed 
at 65-71° C. (150-160° F.) for an hour, with the addition of 2 
to 5 ounces of salt per gallon of liquor. After dyeing, the ma- 
terial is hydroextracted and allowed to oxidize in the air for 2 to 
3 hours. It is then rinsed and soaped in a bath containing 50 
ounces of olive oil soap per hundred gallons at 71° C. (160° F.) 
for one-half hour. With Ciba Violet or mixtures containing it, 
after oxidation in the air, the goods should receive an additional 
treatment for a half hour at 71° C. in a bath containing 2 per cent 
of 40 per cent acetic acid, on the weight of the goods. It is then 
rinsed again and soaped as above. The formulas in Table XXX 
will give an idea as to the dyes and amounts used to obtain the 
various shades on Celanese. 


208 


ACETATE SILK 


TABLE XXX 
CoLors ON CELANESE WITH C1BA DYES 


a 


Bambing. = vee ee ere iy 


Canary cc: faerie Mec ea ee 3: 


Putty es ee ee ee ees 


Pangerines v2: cs ieee ees 


Mignonette i). .mn ores 


Ciba Blue 2G powder 
Ciba Scarlet G extra powder and 
Ciba Yellow G paste 
Ciba Blue 2B powder 
Ciba Orange G paste and 
Ciba Red G powder 

Ciba Pink B powder and 
Ciba Violet B powder 
Ciba Yellow G paste 
Ciba Orange G paste 
Ciba Red G powder and 
Ciba Indigo R paste, 20% 
Ciba Pink G powder 
Ciba Blue 2B powder 
Ciba Orange G paste, and 
Ciba Red G powder 

Ciba Red G powder 

Ciba Orange G paste 
Ciba Red G powder and 
Ciba Blue 2B powder 
Ciba Blue 2G powder 
Ciba Blue 2B powder 
Ciba Orange G paste and 
Ciba Red G powder 

Ciba Orange G paste and 
Ciba Pink BG paste 
Ciba Blue 2B powder 
Ciba Orange G paste and 
Ciba Red G powder 
Ciba Blue 2B powder 
Ciba Orange G paste and 
Ciba Red G powder 
Ciba Brown R paste 
Ciba Red G powder and 
Ciba Orange G paste 
Ciba Violet 3B powder and 
Ciba Blue 2B powder 
Ciba Indigo R paste 20% 
Ciba Orange G paste and 
Ciba Red G powder 
Ciba Blue 2B powder 
Ciba Orange G paste 
Ciba Red G powder 
Ciba Orange G paste and 
Ciba Yellow G paste 
Ciba Orange G paste 
Ciba Brown R paste and 
Ciba Yellow G paste 
Ciba Blue 2B powder 
Ciba Orange G paste and 
Ciba Yellow G paste 


Mate DIRECT DYES 209 


TABLE XXX 
COLORS ON CELANESE WITH C1BpA Dyes 


0.20% Ciba Blue 2B powder 
1.30% Ciba Orange G paste and 
0.08% Ciba Red G powder 
0.7% Ciba Blue 2B powder 
9.0% Ciba Orange G paste and 
0.3% Ciba Red G powder 
POETIC OW eyes oe cbs oe 12.0% Ciba Yellow G paste and 
8.0% Ciba Orange G paste 
1.0% Ciba Red G powder 
0.12% Ciba Violet B powder and 
0.6% Ciba Orange G paste 
2.8% Ciba Indigo R paste 20% 
35.0% Ciba Orange G paste, and 
.2% Ciba Red G powder 
.14% Ciba Violet 3B powder 
.65% Ciba Blue 2B powder 
.5% Ciba Orange G paste and 
.16% Ciba Red G powder 
9% Ciba Orange G paste and 
.01% Ciba Red G powder 
9% Ciba Blue 2B powder 
.0% Ciba Orange G paste and 
.22% Ciba Red G powder 


1 
SSE 4 a 0 
0 
7 
0 
0 
0 
0 
S 
0 
OS Otay 2.0% Ciba Blue 2G powder 
2 
36 
2 
0 
0 
38 
10 


LES tapenade 


Bt OY ee ve bois cw es .9% Ciba Indigo R paste 20% 
.0% Ciba Orange G paste and 
0% Ciba Red G powder 

9% Ciba Red G powder 

.2% Ciba Pink BG powder 
.0% Ciba Green G paste and 
.0% Ciba Yellow G paste 
AOE ce Or 8.0% Ciba Blue 2B powder 


No doubt many of the Helindone vat dyes can be applied by 
Method No. 54, only using formulas along the line of those usually 
given for Helindone dyes on wool.2, Durindone Red Y, Ciba Blue 
and Indigo Blue paste have also been mentioned in the literature as 
applicable to acetate silk. Perhaps Method No. 101 (sodium 
phenolate) may also be useful in applying certain vat dyes to ace- 
tate silk. 

Most of the Indanthrene vat dyes of the older classifications do 
not appear to be particularly applicable to acetate silk by the regu- 
lar hydrosulfite vat methods on account of the high alkalinity of 
the dye bath required to hold them in solution. However, some 
of them, as well as certain Caledon vats, have some application to 


210 ACETATE SICK 


the cotton of acetate silk-cotton unions, but extreme care must be 
exercised to avoid saponification of even the Lustron variety of 
acetate silk. Many of them may be applied to the acetate silk 
by the saponification process which will be discussed later. 

Method No. 55: Indigo on Acetate Silk. Indigo may be applied 
to acetate silk superficially from a fine suspension in water as in 
the dispersol process, or the fiber may be dyed to deep blue 
shades from the regular leuco-indigo vat containing glue and a 
small quantity of hydrosulfite and ammonia, similar to Method. 
No. 54. Indigosol, the new soluble form of indigo, does not appear 
to have quite as much affinity for acetate silk as leuco-indigo ap- 
plied by the above method. The same may be said of the Soledon 
dyes, while the same vat dyes, by the dispersol process, sometimes 
have considerable affinity for acetate silk. 

The Indophenols are more or less obsolete as dyes on the older 
fibers but according to Lawrie,’ they may be useful on acetate 
silk. These dyes belong to the naphthoquinonemonoimide series. 
Lawrie states that Indophenol may be applied to acetate silk 
according to Method No. 56. 

Method No. 56: Indophenol on Acetate Silk. Prepare the dye 
vat with 10 parts of Indophenol to each part of 76° Tw. (1.38 sp. 
gr.) sodium hydroxide solution, and 7.5 parts of hydrosulfite 
powder. This gives a good deep blue but the color is very sensi- 
tive to alkalies. It is possible that the use of an ammonia salt, 
such as the acetate, chloride, or sulfate, may have some protective 
action on the acetate silk from the alkali. Also a colloid such as 
glue might assist this protective action. 

British Patent No. 214,112, May 20, 1923, to W. Kilby and 
Morton Sundour Fabrics states that acetate silk may be dyed by 
means of the alkaline (sodium hydroxide) hydrosulfite vat with 
amino- or nitro- derivatives of anthraquinone or their alkyl or 
halogen derivatives. The derivatives containing hydroxy groups 
have a decreased affinity for this fiber. Compounds such as a- 
aminoanthraquinone (yellowish-orange) ; B-aminoanthraquinone 
(lemon yellow); 1, 5-dinitroanthraquinone (yellowish-orange) ; 
1, 5-diaminoanthraquinone (orange) ; 1, 4-diaminoanthraquinone 
(reddish-violet) ; 1-methylaminoanthraquinone (pinkish-red); 1- — 


THE DIRECT DYES 211 


amino-2, 4-dibromoanthraquinone (yellowish-orange) ; 1-nitro-4- 
chloroanthraquinone ; 1-methy]l-2-aminoanthraquinone, and 1-ami- 
no-5-chloroanthraquinone, are applicable by this method. In suit- 
able instances the dye may be diazotized on the fiber and coupled 
with developers such as B-naphthol, whereby different shades are 
obtained. 

According to British Patent No. 220,505, March 17, 1923, to 
the British Celanese Company, and United States Patent No. 
1,545,819, July 14, 1925, to G. H. Ellis but assigned to the Amer- 
ican Cellulose and Chemical Company, which appears to cover the 
same process, certain dyestuffs of the aryl- or substituted aryl- 
benzo- or naphthoquinonemonoimide series (Indophenols) have a 
very good direct affinity for acetate silk, giving blue and violet 
shades not directly obtainable with azo dyes. It had formerly 
been proposed, in British Patent No. 219,349 which will be dis- 
cussed with the dispersol patents, to apply the Indophenols by the 
dispersol process. The present method covers their application 
from the usual alkaline hydrosulfite vat. These leuco-compounds 
are readily absorbed by the acetate silk fibers and upon oxidation, 
either in the air or by means of hypochlorites, peroxides, or other 
oxidizing agents, colors are obtained which are usually fast to soap- 
ing and light. 

For example, a deep royal blue may be obtained on 100 kilo- 
grams of acetate silk by dissolving a kilogram of dimethyl-p- 
aminophenyl-1,4-naphthoquinonemonoimide and an equal weight 
of sodium hydroxide in a hundred liters of water. This is re- 
duced with 2 kilograms of sodium hydrosulfite, and when reduc- 
tion is complete, filtered into the 30 to 1 dye bath at 50° C. (122° 
F.), already containing 0.5 gram of sodium hydrosulfite and 2 
cubic centimeters of concentrated ammonia, per liter: The material 
is worked for about an hour and a half, adding alkali or hydro- 
sulfite as required to hold the dye in solution, after which the ma- 
terial is rinsed in cold water and finally oxidized in a bath contain- 
ing 2 grams per liter of sodium perborate at 40° C. (104° F.) 
for 30 minutes. 

British Patent No. 233,813, February 27 and November 22, 
1924, to the British Dyestuffs Corporation, J. Baddiley and H. 


212 ACETATE SILK 


Browning, Jr., states that acetate silk may be dyed by means of 
aqueous suspensions (dispersol method) of vat dyes of the indigo 
class, as well as certain indophenol dyes in the reduced or unre- 
duced form. (See British Patents No. 219,349 and No. 220,505.) 
This patent covers the use of quinoneanilides and their substitution 
products and homologues, such as the thiazines, azines, or Oxa- 
zines, in the ordinary hydrosulfite vat at 20° C. (68° F.), with a 
minimum of alkali so that the acetate silk is not appreciably hydro- 
lyzed. Deep shades are readily obtained. For example: The 
condensation product of benzoquinone and p-chloraniline dyes 
acetate silk a brownish-yellow shade; that from a-naphthaqui- 
none and diphenylamine gives a violet shade; while the product — 
obtained by treating the base derived from B-naphthaquinone-4- 
sulfonic acid and p-toluidine with sulfur dichloride, gives red 
shades. Many other examples are also given. 

In United States Patent No. 1,546,969, July 21, 1925, R. Clavel 
covers the same process as British Patent No. 191,553, given under 
the sulfur dyes and protects a process for dyeing acetate silk with 
vat dyes, such as bromoindigo or pyrogene indigo, by means of a 
hydrosulfite vat kept weakly alkaline with ammonia, caustic alkali — 
only being added in sufficient quantity to form the leuco compound — 
of the dye. The dye vat should also contain a protective colloid — 
such as gelatin, glucose or starch, and at least one water soluble 
salt, as for instance the chloride of calcium, magnesium, or barium. — 

United States Patent No. 1,532,427, given under the dyeing 
“assistants,” Chapter X, covers the application of certain vat dyes, — 
such as Indanthrene Blue GCD paste (C. I. No. 1113) with sodium 
dicresyl phosphate, protective colloids, alkali and hydrosulfite. 
United States Patent No. 1,398,357 and British Patent No. 158,340, — 
Chapter X, cover a method of increasing the affinity of the vat 
dyes for acetate silk by means of ammonium thiocyanate. | 


References 


17. F. Briggs, J. Soc. Dyers and Colourists 37, 287-96 (1921). 

2C.E. Mullin, American Dyestuff Reporter 13, 809-15 (1924). 

®L. G. Lawrie, J. Soc. Dyers and Colourists 40, 69-74 (1924) and Amer- 
ican Dyestuff Reporter 13, 593 (1924). 


CHAPTER XVI 


THE DEVELOPED OR AZOIC COLORS ON ACETATE 
SILK 


The Theory, Patents, and Components Used, As Well As The 
Methods of Application. The O-xidized Blacks 


ACETATE silk has a decided affinity for the organic bases, such 
as p-nitroaniline, m-nitro-p-toluidine, dianisidine, a-naphthyla- 
mine, benzidine, etc., and these bases may then be diazotized and 
developed on the fiber, with suitable naphthols or phenols, to give 
a wide variety of colors. As most of these bases are comparatively 
insoluble in water, they are usually converted into their hydrochlo- 
rides, which are water soluble, before being placed in the dye bath. 
They are then applied either as the hydrochloride, or by what is 
generally a more satisfactory process, the hydrochloric acid pres- 
ent may be neutralized in the bath, by the addition of alkali, 
thus precipitating the free base in the dye bath as a fine sus- 
pension. These free bases, in the form of a very fine aqueous sus- 
pension, have a much greater affinity for the acetate silk fiber than 
their hydrochlorides. For this reason the two different methods 
of application frequently give quite different shades on the fiber. 
Pokorny” obtained excellent results on a laboratory scale by dis- 
solving the insoluble intermediate (base) in alcohol and pouring 
this into cold water; or by adding alcohol to the aqueous solution 
of the water soluble intermediate, in order to produce a fine sus- 
pension. 

Many nitrogen compounds have a decided affinity for acetate 
silk and this is particularly the case with the amino compounds. 
In fact Greenhalgh? points out that acetate silk has a greater affinity 
for this group than almost any other group found in dyestuffs 
and says that in some cases under certain conditions, it is difficult 
to completely diazotize the amino group of compounds on the 
acetate silk fiber, which he attributes to its high affinity for the 
cellulose ester. 


213 


214 ACETATE SILK 


In applying the developed colors to acetate silk it is advisable 
to use just the reverse of the usual method of applying them to 
cotton. In other words, instead of padding the fiber with the 
naphthol and then developing the color in a bath containing the 
diazotized base or amine, as on cotton, the acetate silk should first 
be treated with base or amine, and this diazotized on the fiber, 
either in the presence of the developing component, or before enter- 
ing the developing bath. This is on account of the much greater 
affinity of the bases for this fiber, than that of the naphthols or 
phenols. If the process as used on cotton is attempted upon ace- 
tate silk, the shades are usually dull, the fastness poor, and the 
results generally unsatisfactory. 

Still another method of applying the free bases to acetate silk 
depends upon the solubility of a number of them in certain dis- 
persing agents, such as those used in the dispersol method of dye- 
ing. The free base is in this way precipitated as a colloid in the 
dye bath and applied in about the same manner as when it is pre- 
cipitated from its hydrochloride. The affinity of these free bases 
for acetate silk is quite considerable, and sufficient, in a number 
of instances, such as benzidine, toluidine, p-p’-diaminodiphenyla- 
mine, etc., to produce a black color on the fiber, even when applied — 
from a cold solution. For more details regarding suitable dis- 
persing agents and the application of the bases by the dispersol 
process, see the dispersol method of dyeing, Chapters XXI, XXII, 
and XXIII. : 

Theoretically, the application of the developed colors to acetate 
silk is very simple, but in actual practice it is not always so easy. 
Frequently it is very difficult to obtain level shades. Compound, 
light, and delicate shades or tints are also usually difficult, but 
heavier shades are easier. Most of the first special dyes for ace- 
tate silk consisted entirely of these bases and a very large number 
of them are still offered upon the market. At the present time 
their main use is for blacks and other fast heavy shades in con- 
nection with the developed dyes on cotton unions, such as hoisery, 
etc., as no really satisfactory direct dyeing blacks have as yet ap- 
peared upon the market for acetate silk. Dort® mentions their use — 
on Celanese for special fast shades of light navy, red, and orange. 


See BieOPED OR AZOIC COLORS 215 


Among the special dyes for acetate silk which consisted either 
entirely or principally of these bases are the Acedronoles of 
Badische, the Acetylines of St. Denis, the Azoniles of M. L. B., 
the Azonines of Cassella, the Azoics of Griesheim Elektron, the 
Azoles of A. G. F. A., certain Ionamines of the British Dyestuffs 
Corporation, the Silkons of Griesheim Elektron, the S. R. A. 
Diazo Solamines and S. R. A. Blacks of the British Celanese Com- 
pany, etc. Quite a few of these bases give a direct color on ace- 
tate silk, without development, but most of these are only light 
shades, while others are practically colorless until developed. 
Those giving light shades directly usually give a considerably 
darker shade upon development, which is generally much faster 
to washing than the direct shade. 

The affinity of basic compounds containing diazotizable amino 
eroups for acetate silk has resulted in their application by almost 
every method evolved for dyeing this fiber. In the early Iona- 
mines, some of which are still in use, they were solubilized by 
means of omega sulfonic acid groups. We have already discussed 
their application by dispersol methods. All through the patent 
literature covering dyes for acetate silk, mention is made that 
certain of the products may be diazotized and developed upon the 
fiber. 

In applying the developed colors on acetate silk, as, for instance, 
black by means of aminoazodimethylaniline, Ionamine A, or S. R. 
A. Black IV, both of which will be discussed in connection with 
the other dyes of these brands, it is best to diazotize and couple 
in the presence of as little light as possible. This point is par- 
ticularly important on acetate silk as the nitrogen containing 
groups in some cases appear to act a little differently than on other 
fibers, probably due to an affinity for the acetate silk, with the 
result that sometimes, in the presence of light, the resulting diazo 
color is off shade, and “should be” blacks are brownish. 

As examples of the use of the bases upon acetate silk, the fol- 
lowing may be of interest. The fiber may be soaked for some 
time in a two per cent aqueous solution of aniline, diazotized in an 
acidified nitrite solution, and developed with a two per cent solu- 
tion of sodium naphtholate, thus producing Sudan I on the fiber. 
Or the impregnated fiber may be treated with a warm acidulated 


216 ACETATE SIEK 


dichromate solution, as described under the oxidized blacks, to 
produce Aniline Black on the fiber. p-Nitroaniline Red (Para 
Red) can be produced on the fiber by first impregnating it with a 
p-nitroaniline solution, rinsing, diazotizing and developing with B- 
naphthol. Primuline may also be diazotized and developed on 
acetate silk to give a wide variety of shades. 

When applied in this manner, aminoazobenzene gives an excell- 
ent yellow which upon diazotization and development with m- 
phenylenediamine becomes brown, with m-toluylenediamine a 
redder shade, with B-naphthol a scarlet, or with resorcinol an 
orange shade. Benzidine gives a rich brown when diazotized and 
developed on the fiber with m-phenylenediamine. o-Anisidine 
and chloranisidine may be coupled with a or B-naphthol, m- 
phenylenediamine or resorcinol to give good shades. Dichloroben- 
zidine coupled with B-naphthol gives a fine crimson, with m- 
phenylenediamine a browner shade, or with chloranisidine a rich 
orange. Dianisidine coupled with B-naphthol gives a fine purple; 
or with a-naphthylamine hydrochloride a rich brownish-red. p- 
Aminodiphenylamine, when oxidized on the fiber gives a splendid 
black, Diphenyl Black, as described under the oxidized blacks. 
Table XXXI gives a list of developed colors on acetate silk. The 
use of sodium acetate to increase the absorption of the bases from 
the dye bath has been suggested. 

Pokorny’ obtained Para Red on acetate silk by impregnating 
the fiber with a fine suspension of B-naphthol, prepared by pour- 
ing an alcoholic solution of the naphthol into water, washing to 
remove the adhering intermediate and treating the fiber with diaz- 
otized p-nitroaniline solution. He also used the reverse process 
in which the fiber was first treated with the diazotized p-nitro- 
aniline and then with the B-naphthol suspension. 

Pokorny’ also used a two bath method, similar to British Patent 
No. 199,754, for the production of Para Red, wherein he dissolved 
equimolecular portions of p-nitroaniline and B-naphthol in sep- 
arate portions of hot alcohol and then poured both of these solu- 
tions into the one bath. After the goods are worked for a few min- 
utes in the fine suspension, they are washed and treated in a second 
bath containing equimolecular portions of sodium nitrite and hy- 


Tiieewiey ELOPED OR AZOIC COLORS 217 


drochloric acid. While the acetate silk is dyed red in this acid 
bath, cotton remains white. 


TABLE XXXI 
SomME Drrect AND DEVELOPED CoLors ON ACETATE SILK 


Developed with 


Constitution Direct B-Naphthol B-Hydroxy-  B-Aminodipheny- 
naphthoic acid lamine 

m-Aminobenzoic acid 

+o-anisidine Yellow Scarlet Magenta Gold 
m-Aminobenzoicacid ++ 

anthranilic acid Yellow Red Bluish-red Olive 
p-Aminosalicyleacid + 

a-naphthamine Yellow Violet Reddish-blue Olive 


5-Acetylamino-2-amino-4- 

methoxtoluene + B- 

hydroxynaphthoic 

acid (hydrolyzed) Blue-violet Greenish-blue Blue Reddish-violet 
m-Aminobenzoic acid 

+ p-xylidene + 
m-phenylenadiamine Red Reddish-brown MReddish-brown Brown 
m-Aminobenzoicacid +2 

-xylidene + a-naphthy- 


lamine Brownish-red Reddish-violet Reddish-blue Brown 
m Aminobenzoicacid -+m- 

toluidene Yellow Scarlet Bluish-red 
Anthranilicacid + 

o-anisidine Orange Bluish-red Reddish-blue wa 
p-Aminobenzoic acid + 

aminohydroquinone- 

methyl] ether Orange Reddish-violet Blue a 
m-Aminobenzoic acid -++ 

4-nitro-2-anisidine Greenish- Reddish-orange Red 

yellow 


m-Aminobenzoic acid 

+1, 2-aminonaph- 

thol ether Red Greenish-blue Bluish-green 
m-Aminobenzoic acid 

-+a-naphthylamine Reddish-orange Reddish-violet Reddish-blue 


He obtained a yellow on acetate silk by treating the fiber with 
an aqueous suspension of Developer Z (phenylmethylpyrazolone), 
prepared by adding alcohol to the aqueous solution of the devel- 
oper. The goods are then washed and passed through diazotized 
p-nitroaniline solution. The same result, except that the shade is 
weaker, is obtained by treating the acetate silk with an aqueous 
solution of the Developer Z, instead of the suspension. 

Green, olive, and brown shades on acetate silk were obtained by 
Pokorny’ by working in an aqueous suspension, prepared by alco- 
hol, of B-naphthol, a-naphthol, dihydronaphthalene, etc. On treat- 
ing this with a solution containing sodium nitrite and hydrochloric 
acid, the corresponding nitroso compound is formed. After wash- 
ing again, the goods are passed through an aqueous solution of 
any salt of iron, cobalt, nickel, copper, or chromium. The result- 
ing colors are very fast to soap. 


218 AGHTIAT Reais 


_ The “Fast Bases,’ Naphthols, and “Rapid Fast’ Dyes on Acetate 
Silk 

Experiments by the author indicate that certain of the Fast 
Bases, such as those marketed by the Griesheim Elektron Company 
and others, are applicable to acetate silk under the proper condi- 
tions. These bases may be diazotized and developed on the fiber 
with suitable developers, as for instance the naphthols AS. L. B. 
Holliday & Company* mentions that Fast Red Base, Fast Scar- 
let Base, Orange Base, etc., may be applied to acetate silk and 
suggest Method No. 57 for their application. It is possible that 
some of the Rapid Fast dyes may be applicable for printing acetate 
silk. These Rapid Fast dyes are faintly alkaline mixtures of 
stabilized diazo compounds and various naphthols. 

The composition of these Fast Bases,® according to Rowe is 
given in Table XXXII. The composition of the naphthols AS 
of Griesheim Elektron are given in Table XXXIII. Certain of 
these naphthols also appear to have some affinity for acetate silk. 
Table XXXIV gives the composition of the Rapid Fast dyes and 
Table XXXV of some Fast Salts. Rowe? also gives tables show- 
ing the colors obtained by coupling a wide variety of bases with 
the various naphthols, etc. While these tables were prepared 
primarily for the identification of the various amines, they give 
some idea as to the color obtained on the fiber from these products. 

Method No. 57: The Fast Bases on Acetate Silk. These bases 
may be applied at about 32° C. (90° F.) in the presence of hydro- 
chloric acid, until equilibrium is reached. The exhaustion is com- 
pleted by the addition of sodium acetate, to neutralize the mineral 
acid present, and by raising the temperature to 65° C. (150° A Sst 
The diazotization and development may be affected by the methods 
given for the special developed dyes on acetate silk. 


Hydrogen Ion Concentration in Coupling 


Before closing this part of the subject, it may be well to point 
out the importance of the hydrogen ion concentration of the coup- 
ling bath, in the development of colors on the fiber. Very possibly 
this subject is even more important in the production of the azo 
dyes in dyestuff manufacture. It is understood that some of the 


THE DEVELOPED OR AZOIC COLORS 219 


European dyestuff manufacturers give this phase of the subject 
considerably more attention than it receives in America. In coup- 
ling on the fiber a proper control of the hydrogen ion concentra- 
tion, along with the suitable control of other factors, of course, 
gives much better results in the matching of shades, as well as a 
considerable economy in the use of the component materials, as it 
gives a practically complete coupling of the constituents. 


TABLE XXXII 
THE COMPOSITION OF THE “Fast BASES” 


‘5 ees eer ce? ee 


Base 


Composition 


Fast Orange R base (Gr.E) 
Fast Garnet B base (Gr. E.) 
Fast Garnet G base (Gr.E.) 
Fast Red B base (Gr.E.) 
Fast Red BB base (Gr.E.) 
Fast Red G base (Gr.E.) 
Fast Red GL base (Gr.E.) 
Fast Red 3GL base (Gr.E.) 
Fast Red 3GL base Special (Gr.E.) 
Fast Red R base (Gr.E.) 
Fast Red RL base (Gr.E.) 
Fast Scarlet G base (Gr.E.) 
Fast Scarlet R base (Gr.E.) 
Fast Blue B base (Gr.E.) 
Fast Black LB base (Gr.E.) 


Fast Yellow G base (Gr.E.) 

Fast Red base GL (JWL) 

Fast Red GL base (Gr.E.) 

Fast Red base RL (JWL) 

Fast Red RL base (Gr.E.) 

Fast Scarlet GL base special (J WL) 
Fast Scarlet G base (Gr.E. 

Fast Scarlet base GCL (JWL) 


Fast Scarlet GC base (Gr.E.) 


Fast Scarlet base 2GL (J WL) 
Fast Scarlet GG base (Gr.E.) 
Fast Yellow base GL (JWL) 
Fast Yellow G base (Gr.E.) 
Fast Yellow base GCL (J WL) 
Fast Yellow GC base (Gr.E.) 
Fast Orange G base (Gr.E.) 
Fast Red KB base (Gr.E.) 


Fast Red TR base (Gr.E.) 
Fast Scarlet TR base (Gr.E.) 


m-nitroaniline 
a-naphthylamine 
0-aminoazotoluene 
5-nitro-2-aminoanisole 
o-anisidine 
3-nitro-4-aminotoluene 
3-nitro-4-aminotoluene 
2-nitro-4-chloroaniline 
2-nitro-4-chloroaniline 
4-chloro-2-aminoanisole 
5-nitro-2-aminotoluene 
4-nitro-2-aminotoluene 
4-nitro-2-aminoanisole 
dianisidine 
2-ethoxybenzeneazo-a-naphthy- 
lamine 
o-chloroaniline 
3-nitro-4-aminoanisole 
3-nitro-4-aminoanisole 
5-nitro-2-aminotoluene 
5-nitro-2-aminotoluene 
4-nitro-2-aminotoluene 
4-nitro-2-aminotoluene 
4-nitro-2-aminotoluene hydro- 
chloride 
4-nitro-2-aminotoluene hydro- 
chloride 
2, 5-dichloroaniline 
2, 5-dichloroaniline 
o-chloroaniline 
o-chloroaniline 
o-chloroaniline hydrochloride 
o-chloroaniline hydrochloride 
m-chloroaniline 
4-chloro-2-aminotoluene hydro- 
chloride 
5-chloro-2-aminotoluene hydro- 
chloride 
6-chloro-2-aminotoluene hydro- 
chloride 


220 ACETATE SILK 


TABLE XXXIIlI 
COMPOSITION OF THE NAPHTHOLS AS (GR.E.) 


Napbhthol Composition 

Naphthol AS B-hydroxynaphthoic acid anilide 
Naphthol AS-BS (also formerly called BS or AN) 

B-hydroxynaphthoic acid m-nitroanilide 
Naphthol AS-RL B-hydroxynaphthoic acid p-anisidide 
Naphthol AS-SW B-hydroxynaphthoic acid B-naphtholide 
Naphthol AS-G diacetoacetotoluide 
Naphthol AS-BR B-hydroxynaphthoic acid dianisidide 
Naphthol AS-TR B-hydroxynaphthoic acid 5-chloro-o-toluidide 
Naphthol AS-D B-hydroxynaphthoic acid o-toluidide 
Naphthol AS-BO B-hydroxynaphthoic acid a-naphthalide 


Ne 
—————— Sa 


TABLE XXXIV 
CoMPOSITION OF ‘‘Rapip Fast” DyEs (Gr.E.) 


ee 
Rapid Fast Red B Mixture of nitrosamine of diazotized 5-nitro-2- 
. aminoanisole and naphthol AS. 

Rapid Fast Red BB Mixture of same nitrosamine and naphthol AS-BS. 
Rapid Fast Red GG Mixture of nitrosamine of diazotized p-nitroaniline 
and naphthol AS. 

Rapid Fast Brown B Mixture of Rapid Fast Red GG and a shading 

powder compound. 
Rapid Fast Red’ 3GL Mixture of nitrosamine of diazotized o-nitro-p- 


chloroaniline and naphthol AS. 

Rapid Fast Blue powder Mixture of naphthol AS and probably tetrazo- 
tized dianisidine. 

Rapid Fast Red GZ Mixture of diazotized 2,4-dichloroaniline and 
naphthol AS. 

Rapid Fast Orange RG Mixture of nitrosamine of diazotized o-nitroani- 
line and naphthol AS. 

Rapid Fast Red GL Alkaline paste of nitrosamine of diazotized m- 
nitro-p-toluidine and naphthol AS. 


TABLE XXXV 
COMPOSITION OF THE ‘‘FAsT SALTS” (GR.E.) 


Fast Red Salt B stabilized diazotized 5-nitro-2-aminoanisole 
Fast Red Salt GG stabilized diazotized 2, 5-dichloroaniline 

Fast Red Salt GL stabilized diazotized 3-nitro-4-aminotoluene 
Fast Scarlet Salt R stabilized diazotized 4-nitro-2-aminoanisole 


The Developed Color Patents 
One of the earliest patented methods of dyeing acetate silk was 
German Patent No. 199,559, February 19, 1907, to Knoll and 
Company. French Patent No, 383,636, November 6, 1907; Brit- 


ay LOPE D ORVAZOIC COLORS 221 


ish Patent No. 24,284, November 2, 1907; and United States 
Patent No. 961,241, June 14, 1910, cover the same process. In 
these patents it was suggested to dye acetate silk with developed 
colors by the aid of solvents or swelling agents, as discussed under 
the solvent methods of dyeing acetate silk, Chapter XVIII. 

In United States Patent No. 979,966, December 27, 1910, to 
E. Knoevenagel, the inventor suggests the use of aqueous solutions 
of phenol, B-naphthol, p-aminophenol, etc., and coupling with 
diazonium salts, in the dyeing of acetate silk. In United States 
Patent No. 1,002,408, September 5, 1911, to the same inventor, 
he suggests treating the fiber with an aqueous solution of an aro- 
matic amine, as for instance aniline, p-nitroaniline, a-naphthyla- 
mine, aminoazobenzene, benzidine or p-aminophenol, to constitute 
one component of a dye formed on the fiber. 

R. Clavel in British Patent No. 187,964, October 27, 1921, covers 
the production of azo colors on acetate silk by adding soluble 
salts to dye baths containing the parent amine, the developer, or 
to both. Chlorides of ammonium, sodium, potassium, barium, cal- 
cium, magnesium, zinc, or tin; or sulfates of sodium, potassium, or 
magnesium are given as suitable salts. Protective colloids, such 
as gelatin, silk boil-off liquor, Turkey-red oils, albumin, tannates, 
soaps, etc., may also be added when the bases or developers are 
used in neutral or alkaline baths. These assistants allow the use 
of baths of lower alkalinity and give a greater absorption of the 
color constituent. 

For example, a kilogram of acetate silk may be dyed black by 
soaking it for 30 to 45 minutes at 60° C. (140° F.) in 20 to 25 
liters of a solution containing 25 grams of dianisidine hydro- 
chloride, 50 grams of magnesium chloride, and 40 grams of sodium 
bicarbonate, and washing. It is diazotized in a bath containing 50 
grams of sodium nitrite and 200 cubic centimeters of concen- 
trated hydrochloric acid for 30 minutes at 15° C. (59° F.) and 
developed -in a 20 or 25 liter bath containing 20 grams of a-naph- 
thylamine hydrochloride, 8 grams of sodium bicarbonate and 50 
grams of magnesium chloride for 1 hour at 65° C. (149° F.). It 
is then washed, diazotized as before, and soaked for an hour at 
65° C, (149° F.) in a slightly alkaline bath containing 20 liters 


222 ACETATE SILER 


of water, 5 liters of boil-off liquor, 30 grams of 5-hydroxy-a-naph- 
thylamine, and 50 grams of magnesium chloride, whereby the 
black shade is developed. A final soaping at 60° C. (140° F.) is 
given. United States Patent No. 1,549,906, August 18, 1925, to 
the same inventor, appears to cover about the same process. Also 
see British Patents No. 176,535, No. 182,830, No. 187,964, No. 
199,754 and No. 204,179. 


The Two Bath Process 


In British Patent No. 199,754, January 5, 1922, and United 
States Patent No. 1,571,320, February 2, 1926, to R. Clavel, he 
suggests in applying the developed colors to acetate silk, that (a) 
the base and developer may be applied in the same bath and then 
diazotized in a second bath; or (b) the base may be applied and 
diazotized in the one bath, developing in the second bath; or (c) 
the base may be applied in one bath, and then diazotized and 
developed in the second bath, in the presence of a suitable protec- 
tive colloid, such as gelatin, silk boil-off liquor, etc. For example, 
one kilogram of acetate silk may be dyed a brownish-red shade by 
working it for a half hour at room temperature in a bath con- 
taining 25 liters of water, 20 grams of aminoazobenzene, 30 grams 
of B-naphthol, 5 grams of Capri Blue (for shading) and 2 liters 
of silk boil-off liquor; afterwards adding 50 grams of magnesium 
chloride and working for one-half hour at 60° C. (140° F.). It 
is then washed, diazotized cold in a bath containing 20 liters of 
water, 50 grams of sodium nitrite and 100 cubic centimeters of 
concentrated hydrochloric acid. 

Another example specifies a 25 liter bath containing 20 grams 
of aminoazotoluene and 2 liters of silk boil-off liquor. After 
working for 30 minutes, 50 cubic centimeters of sulfuric acid and 
50 grams of sodium nitrite are added. Wash and develop in a 
60° C. (140° F.) bath containing 25 liters of water, 30 grams of 
B-naphthol and 50 grams of soap. 

Burgess, Ledward & Company and W. Harrison obtained 
British Patent No. 193,646, February 4, 1922, on a single bath 
process of forming azo colors on acetate silk. In this process the 
silk is steeped in a bath containing the amino or/and phenolic com- 


Pee VELOPED OR AZOIC COLORS 223 


ponents of the color, subsequently adding sodium nitrite and then 
acid, whereby the color is developed. Temperatures between 30 
and 80° C. (86 to 176° F.) are specified and when the resulting 
dye tends to form a precipitate in the bath, a protective colloid, 
such as gelatin or starch is added. These colors may be topped 
with basic or other dyes. 

For example, a red color is obtained on 100 parts of acetate 
silk by treating it at 60° C. (140° F.) in a bath of 4000 parts of 
water, containing 2 parts of aminoazobenzene dissolved in 2 
parts of hydrochloric acid. After 30 minutes, 10 to 20 parts of 
sodium acetate are added to aid the exhaustion, and after a further 
30 minutes, 2 parts of glue dissolved in water, and 2 parts of B- 
hydroxynaphthoic acid dissolved in water containing 2 parts of 
ammonia. After a further 15 or 20 minutes, 0.7 part of sodium 
nitrite and 10 parts of formic acid are added, the temperature 
being maintained at 60° C. (140° F.). Finally a further 0.7 part 
or more of sodium nitrate is added, whereby the silk develops a 
full red shade, which may be topped with Butter Yellow or Nile 
Blue. | 

A navy blue on 100 parts of acetate silk may be obtained by 
treating it in a bath containing 2 parts of dianisidine, 2 parts of 
36° Tw. hydrochloric acid and 4000 parts of water at 50 to 70° 
C. (122 to 158° F.) for 15 minutes. Two parts of glue dissolved 
in hot water, and 4 parts of B-hydroxynaphthoic acid dissolved in 
20 parts of hot water containing 2 parts of 0.88 sp. gr. ammonia 
are added, and in 15 or 20 minutes 1.2 parts of sodium nitrite in 
4 parts of water and 15 parts of 90 per cent formic acid are intro- 
duced. After working for 30 minutes, 1.2 parts more of sodium 
nitrite are added and the treatment continued for another 30 
minutes. A black shade is obtained from 1-aminobenzene-4-azo- 
dimethylaniline and B-hydroxynaphthoic acid. The dyeings may 
be made purer and clearer by an after-treatment with reducing 
agents, such as formaldehyde-hydrosulfite or stannous chloride in 
acid solution. 

In British Patent No. 204,179, July 28, 1922, R. Clavel states 
that in the production of azo colors on the acetate silk fiber, the 
development may be effected at temperatures of from 60° C. 


224 ACETATE SILK. 


(140° F.) to boiling (100° C. or 212° F.) and that the application 
of the bases may take place at the same high temperatures. The 
bases and developers may be applied in separate baths or in a com- 
bined bath, the diazotization taking place in a separate bath at 
ordinary or low temperatures. Readily hydrolyzable salts of strong 
bases, such as sodium acetate, or free bases such as sodium hydrox- 
ide, may be added to the base baths, and acids or acid salts, such as 
hydrochloric or acetic acids or sodium hydrogen phosphate, to the 
developing baths. Protective colloids such as gelatin, silk boil-off 
liquor, or sulfonated fatty acid soaps may be used with these, and 
soluble salts, such as the chlorides of magnesium, ammonium, zinc 
or tin may also be added to the baths. 

British Patent No. 200,873, which will be considered under the 
Ionamines, also refers to the development of colors on acetate 
silk. British Patent No. 202,157 and United States Patent No. 
1,498,315, discussed under the acid dyes, cover the application to 
acetate silk of carboxylated aminoazo dyes, which may be diazo- 
tized on the fiber and developed. British Patent No. 214,112, dis- 
cussed under the vat dyes, covers the diazotization and develop- 
ment of dyes on the fiber which were applied from an alkaline 
hydrosulfite vat. British Patent No. 224,359, under the dispersol 
dyes, covers the application of many bases by the dispersol process. 
Also see British Patent No. 245,790. 

British Patent No. 231,455, March 31, 1924, to the Society of 
Chemical Industry, Basle, states that acetate silk may be dyed 
fast shades of violet, green, and blue to black with monoazo dyes 
containing at least one diazotizable amino group, then diazotizing 
on the fiber and developing with an alkyl- or aralkyl-a-naphthy- 
lamine. For example, ten parts of acetate silk are dyed with 5 per 
cent of the dyestuff from diazotized o-chloroaniline and a-naph- 
thylamine-2-sulfonic acid. The material is then washed, diazotized, 
washed again, and developed in a bath containing 3 per cent of an 
alkyl-a-naphthylamine on the weight of the goods, whereby it is 
dyed a blue-black shade of excellent fastness. 

French Patent Application No. 25,785, of 1924, covers the appli- 
cation of a developed black on acetate silk by a rather involved 
process. A kilogram of acetate silk is treated for 30 or 45 min- 


Se 


ieee OPED OR AZOIC COLORS 225 


utes in a 25 liter bath containing 20 grams of dianisidine salt, 50 
grams of magnesium chloride and 40 grams of sodium bicarbonate. 
The impregnated fiber is washed, first in soft water, followed by 
hard water. The diazotization is affected in a 20 liter bath con- 
taining 50 grams of sodium nitrate and 200 grams of hydrochloric 
acid. The diazotized material is developed for an hour in a bath 
containing 20 grams of naphthylamine hydrochloride and 8 grams 
of sodium bicarbonate, after which it is washed. Replace the 
goods in the developing bath for some time, rewash, and treat for 
an hour in a 20 liter bath containing 5 liters of filtered soap solu- 
tion, 85 grams of aminonaphthol (gamma acid), and 50 grams of 
magnesium chloride. A final washing with water at 60° C. (140° 
F.), followed by a soap washing, concludes the treatment. Also 
see British Patent No. 187,964 above. 

German Patent No. 428,176, March 1, 1924, to K. H. Meyer 
and H. Hopff assigned to the I. G. Farbenind. A.-G., acetate silk 
may be dyed in shades fast to washing by means of slightly water- 
soluble, feebly basic nitroarylamines or their derivatives. Suitable 
orange-yellow, greenish-yellow, rddish-yellow, and yellow dyes are 
8-nitro-2-naphthylamine, 3-nitro-4-aminobenzophenone, 4-nitro-2- 
aminodiphenylamine, and the condensation product of 3-chloro-6- 
nitroaniline and formaldehyde. 


Oxidized Blacks on Acetate Silk 


Briggs,® in an excellent review of the subject of dyeing acetate 
silk up to 1921, states that the affinity of acetate silk for the aro- 
matic amines makes it especially adaptable for aniline black dyeing. 

Method No. 58: Aniline Black on Acetate Silk. The acetate 
silk is treated with a dilute aqueous solution of aniline hydro- 
chloride and then impregnated with strong aniline hydrochloride, 
chlorate, and copper liquor. It is then whizzed, hung up, and 
oxidized for an hour or an hour and a half at 40 to 60° C. (104 to 
140° F.), after-treated with acid bichromate, and shaded up. 

In United States Patent No. 1,448,482, R. Clavel states that 
aniline black can be brought into acetate silk either direct or in 
suspended form, but better by impregnating the fiber with aniline 
hydrochloride and developing. Practical application of this latter 


226 ACETATEISIER 


method (impregnation) has shown, in spite of its economy, that 
the fiber is sometimes injured and the process is not entirely satis- 
factory. He has therefore superceded this method by United 
States Patent No. 1,547,789 and British Patent No. 194,840. 

British Patent No. 194,840, January 5, 1922, and United States 
Patent No. 1,547,789, July 28, 1925, to R. Clavel, cover a process 
for obtaining black shades on acetate silk by means of Diphenyl 
Black Base (p-aminodiphenylamine). The affinity of this fiber 
for amino, imino and acidylamino compounds is utilized by 1m- 
pregnating the fiber with Diphenyl Black Base, in the presence of 
an acid, such as acetic acid, and a soluble chloride, with or without 
protective colloids, and then oxidizing the base on the fiber. 

Method No. 59: Black on Acetate Silk with Diphenyl Black 
Base. A stock solution is prepared containing 200 grams of Di- 
phenyl Black Base, 500 cubic centimeters of 80 per cent acetic 
acid and 500 cubic centimeters of water. For 1 kilogram of ace- 
tate silk, take 250 cubic centimeters of the above stock solution 
in 20 liters of water and 2 liters of silk boil-off liquor. Heat the 
bath to 50° C. (122° F.) and work the goods for an hour. Add 
50 grams of sodium acetate and work the material for another 
hour at 60° C. (140° F.). Rinse and oxidize by the addition of 
three portions of 25 grams each of sodium perborate, at intervals 
of 20 minutes, after which the goods may be washed or brightened. 
The perborate may be replaced by hypochlorite or ammonium per- 
sulfate. 

Method No. 60: Black on Acetate Silk with Diphenyl Black 
Base. Another method covered by the same patent utilizes stock 
solutions (4) containing 200 grams Diphenyl Black Base, 550 
cubic centimeters of 50 per cent acetic acid and 250 cubic centt- 
meters of 50 per cent lactic acid made up to 1250 cubic centimeters ; 
and (B) containing 125 grams of 30° Be. (sp.gr. 1.26) aluminum 
chloride, 125 grams of 30 Be. chromium chloride, 20 grams of 40° 
Be. (sp. gr. 1.38) cupric chloride and 150 grams of sodium chlor- 
ate in each 1250 cubic centimeters. Seven hundred and fifty cubic 
centimeters each of A and B are mixed and diluted to 4.5 to 6.5 
liters, and the acetate silk steeped in this bath, cold, turning the 
goods two or three times. Remove the goods from the bath, 


ding é 


Poe OPED OR AZOIC COLORS 227 


hydroextract, dry and age for an hour at 80° C. (176° F.). Wash 
and soap at 50 to 60° C. (122 to 140° F.), rinse well and finally 
sour. About 12 per cent of Diphenyl Black Base, on the weight 
of the goods, is necessary for a good black. Also see United States 
Patent No. 961,241 covering aniline black and other methods. 

Pokorny’ prepared Aniline Black on acetate silk by working the 
goods for a few minutes in a fine aqueous suspension of 10 grams 
of Diphenyl Black Base I (M.L.B.) in 10 liters of water. After 
washing, the black is developed by working the well squeezed or 
hydroextracted goods for a few minutes in an oxidizing solution. 
This oxidizing solution contains 10 grams of ammonium chloride, 
10 grams of sodium chlorate and 200 grams of vanadium solution 
in 10 liters of water. The vanadium solution is prepared by 
heating 10 grams of ammonium vanadate and 100 cubic centi- 
meters of 34° Tw. hydrochloric acid on a water bath with 400 
cubic centimeters of water until it is completely dissolved to 
form a green solution. Five cubic centimeters of glycerol are 
then added and the solution treated until the color changes to 
blue. This is diluted to 10 liters with water. The goods are again 
squeezed and steam oxidized with saturated steam, without pres- 
sure. With the dilute solutions mentioned above, repeated treat- 
ments are necessary to obtain the deepest blacks. 

British Patent No. 255,962, to the British Celanese Company 
and G. H. Ellis states that processes involving the oxidation of 
aniline, p-aminophenol, p-phenylenediamine, p-aminodiphenylam- 
ine, benzidine, tolidine, a-naphthylamine, or other amino com- 
pounds may be used on acetate silk by absorption of the base from 
aqueous solutions or dispersions, followed by treatment with a 
suitable oxidizing agent.. The amino impregnated fiber is rinsed 
and impregnated with suitable oxidizing agents, such as chlorates, 
hypochlorites, or bichromates. These may be used in conjunction 
with such catalysts as the salts of vanadium, iron, and copper, 
and such soluble salts as sodium sulfate, or the chlorides of am- 
monium, barium, calcium, and magnesium may be added. Sodium 
or calcium acetate may be added to the solution of the organic 
base, when it is used in the form of an acid salt liable to cause 
tendering. After drying, the material is aged in an atmosphere 
of warm moist air. 


228 ACHE TA TR Shale 


The inventors state that in the past some of the oxidized colors 
on acetate silk have not been very satisfactory, due to the frequent 
blinding of the fiber and crocking of the color. This rubbing oc- 
curred when both the one- and two-bath dyeing processes were 
used. However, they find that when the amino compound is ap- 
plied to the acetate silk by the usual dispersol process (see Chap- 
ters XXI to XXIII) the absorption is more gradual, and better 
results, as regards to rubbing, are obtained. 

For example: ten pounds of acetate silk in hanks may be dyed 
a full deep black by dissolving 0.75 pound of p-aminodiphenyl- 
amine base in 6 pounds of 50 per cent Turkey-red oil, diluting with 
water and heating to 80° C. (176° F.) for a short time to effect 
solubilization or dispersion. This is diluted with hot water and 
added through a filter cloth to a 25 gallon dye bath at 80° C. The 
acetate silk is entered at this temperature and worked for 2 hours. 
After rinsing with soft water the goods are impregnated cold with 
their own weight of an oxidizing solution prepared as follows: 
Dissolve 2 parts of gum tragacanth in 300 parts of water; 8 parts 
of chromium chloride in 56 parts of water; 4 parts of aluminum 
chloride in 50 parts of water; 3 parts of cupric chloride in 50 
parts of water; and 60 parts of sodium chlorate in 120 parts of 
water. Add water to 1000 parts. The goods are now aged, pre- 
ferably after drying at a moderate temperature, for 5 minutes in a 
steam ager, and washed off in hot water or very dilute formic acid 
(about one cubic centimeter per liter) to remove mineral matter. 
The yarn has now acquired a dead black color, the luster and 
handle being unimpaired, and may be dried and finished as re- 
quired. 

In another example, the same weight of yarn is dyed a medium 
brown shade by 0.5 pound of benzidine. This is dispersed or dis- 
solved as above with 2.5 pounds of dispersing agent prepared by 
sulfonating a mixture of naphthalene and oleic acid (Twitchell 
reagent). This is diluted with soft boiling water and filtered into 
the 25 gallon dye bath. The goods are entered, the temperature 
raised to 70 or 75° C. (158 or 167° F.) in about 45 minutes and 
worked at this temperature for an hour. They are then rinsed 
and the base oxidized by the impregnation and ageing process 


Perv ELOPED OR AZOIC COLORS 229 


given in the previous example. After rinsing in the dilute formic 
acid bath, the goods are a dull brown shade. 

In the same manner a fawn-brown shade may be obtained with 
0.5 pound of p-aminophenol at 70 to 75° C., and oxidizing as 
above. 

One-half pound of p-phenylenediamine at the same temperature 
is used to obtain a deep brown color. After rinsing, the goods are 
impregnated with a bath made up as follows: Two parts of gum- 
tragacanth in 300 parts of water; 4 parts of aluminum chloride in 
50 parts of water; 3 parts of cupric chloride in 50 parts of water ; 
and 150 parts of sodium bichromate in 100 parts of water. Add 
water to make 1000 parts. After squeezing evenly so that the fiber 
contains only its own weight of the oxidizing mixture, it is aged 
for 5 minutes in a steam ager and rinsed in very dilute formic acid. 

British Patent No. 258,699, July 10, 1925, to the Silver Springs 
Bleaching and Dyeing Company and A. J. Hall states that acetate 
silk may be dyed in very fast black shades by the application of 
2,-4-diaminodiphenylamine from aqueous solutions or suspensions 
and subsequent immersion in hot or boiling aqueous solutions of 
oxidizing agents (see British Patent No. 246,879). Or the goods 
may be impregnated with a paste containing an oxidizing agent, 
a catalyst, an acid, and 2,4-diaminodiphenylamine followed by 
exposure to a moist warm atmosphere for development of the 
black color. Mixtures containing 2,4-diaminodiphenylamine and 
one or more aromatic amines, such as aniline, o-toluidine, p-phenyl- 
enediamine, and p-aminodiphenylamine may be used. Ferric chlo- 
ride, permanganates, chlorates, perborates, hydrogen peroxide, and 
bromine are mentioned as suitable oxidizing agents. The oxida- 
tion of 2,4-diaminodiphenylamine on acetate silk will take place 
by exposure to air alone, giving a full black, even in the absence 
of light. 

For example, 10 parts of acetate silk are immersed for an hour 
at 40.5° C. (105° F.) ina bath containing 0.75 part of 2,4-diamino- 
diphenylamine, 0.6 part of soap, 0.6 part of 0.920 sp. gr. ammonia 
and 300 parts of water. It is then rinsed in warm water and 
immersed for a half hour at 65.5 to 71° C. (150 to 160° F.) ina 
bath containing 4 parts of sodium chlorate, 25 parts of hydro- 


230 ACETATE SILK 


chloric acid, 1 part of copper sulfate, and 300 parts of water, then 
rinsed in warm water, soaped at 60° C. (140° F.), rinsed in warm 
water and dried. 


References 


21&, Greenhalgh, Dyer and Calico Printer 55, 146 (1926). 
2R. G. Dort, American Dyestuff Reporter 15, 266 (1926). 
W.E. Sanderson, J. Soc. Dyers and Colourists 38, 162-5 (1922). 
‘L. B. Holliday & Company, “Application and Properties of Dyestuffs,” 
p. 94. 
» SEM. Rowe, J. Soc. Dyers and Colourists 37, 204-15 (1921) ; 40, 218-30 
(1924) ; 41, 354-6 (1925) ; 42, 82-3 (1926). 
°J. F. Briggs, J. Soc. Dyers and Colourists 37, 287-96 (1921). 
7J. Pokorny, J. Soc. Dyers and Colourists 42, 345-8 (1926). 


CHAPTER XVII 


Peete COMPONENTS FOR THE DEVELOPED OR 
fee COLORS ON ACETATE SILK 


The Acedronoles, Acetylines, Agoniles, Azonines, Azoics, Azoles, 
Silkons, and Other Special Azgoic Color Components on Acetate 
Sik. 


WHILE the products to be discussed in this chapter do not have 
a very wide use upon acetate silk at the present time owing to the 
greater ease of application of the many new dyes originated espe- 
cially for use upon acetate silk, they are still used to some extent 
for special purposes. As mentioned in Chapter XVI, most of the 
products under discussion here are in reality well-known bases, 
amines, phenols, etc., which have more or less use for the other 
purposes in the dyestuffs or dyeing industry, either as dyestuff 
components or intermediates, or in the development of similar 
colors on other fibers. However, their methods of application to 
acetate silk are usually quite different from their application to 
other fibers, such as cotton. The principal justification for in- 
cluding a chapter on these products in the present volume is that 
at the present time the developed blacks are the most satisfactory 
offered for acetate silk, and that the developed colors are used to 
some extent for very fast and heavy shades on hosiery, etc. 


The Acedronoles 


The Acedronoles of the Badische Company belong to the class 
of products under discussion. These products are applied to the 
scoured but unsaponified acetate silk by Method No. 61. Method 
No. 61-A covers the diazotization, and No. 61-B the development. 
Table XXXVI gives a list of the colors obtained, the developers 
used, and the amount of sodium acetate, where this is required. 
Most of these combinations leave the cotton of acetate silk-cotton 
unions either white or only slightly stained and are therefore suited 


231 


232 ACETATE SILK 


for two color combinations on acetate silk-cotton unions. How- 
ever formulas No. X7, No. X8, No. X32, No. X33 and No. X43 
stain cotton and the regenerated rayons considerably. 

Acedronoles AB, AN, AT, BN, BT, CA, and ND are available 
both as 30 per cent pastes and in powder form, while B, DA, and 
- T are in the form of 30 per cent pastes. In preparing the Aced- 
ronole dye bath the Acedronoles B, BT, DA, and T are dis- 
solved in hot water without any addition. Acedronoles AN, BN, 
CA and ND are wet-out with 50 to 100 times their weight of 
boiling water and dissolved by the addition of double their weight 
of concentrated hydrochloric acid. In other words, each pound 


of Acedronoles AN, BN, CA, and ND is mixed with 6 to 12. 


gallons of boiling water and then 2 pounds of hydrochloric acid is 
added to complete the solution. 

Acedronole AB is dissolved by mixing it with 10 times its weight 
of cold 85 per cent formic acid, adding about 100 times its weight 
of boiling water, and then about 4 volumes of concentrated hydro- 
chloric acid, to complete the solution. In other words, each 100 
grams (about 3.5 ounces) of Acedronole AB should be mixed with 
a liter (slightly over a quart) of formic acid, adding about 10 liters 
(2.7% gallons) of boiling water, and after stirring well, 400 cubic 
centimeters (about 13.8 fluid ounces) of hydrochloric acid. 

Acedronole AT is dissolved in exactly the same way as Ace- 
dronole AB, except that just twice the amount of hydrochloric 
acid given for-AB is used. In other words, for 100 grams of AT, 
use 1 liter of formic acid, 10 liters of boiling water and 800 cubic 
centimeters (about 27.5 fluid ounces) of concentrated hydrochloric 
acid. 

Acedronoles ND, CA, BN, AN, DA, T and B may be mixed 
together in any proportions in the dye bath and Acedronoles AB 
and AT may also be used together, but should not be mixed with 
the above on account of the difference in the acidity of their baths, 
which may cause precipitation of the Acedronoles AB and AT in 
the less acid bath. Sodium acetate is not used with Acedronoles 
AB, AT, and BT. 

Method No. 61: The Acedronoles on Acetate Silk. The dye 


a 


tee cle. sea” Seek ey wow mianens 


pPLCIAL. COMPONENTS 233 


bath is prepared by straining the above Acedronole solution 
through cotton into the 20 to 1 dye bath at about 40° C. (104° F.). 
The scoured acetate silk is entered at this temperature and worked 
for about 15 minutes. The temperature is raised to 60 or 70° C. 
(140 or 160° F.) and the handling continued for about a half-hour. 
Where required, as given in Table XXXVI, the stated quantity of 
sodium acetate, in solution, is then slowly added to the bath to 
aid exhaustion. After a further working for about a half-hour, a 
rinse of cold water is given and the acetate silk is ready for 
diazotization. 

Method No. 61-A: Diazotizing the Acedronoles. The diazotizing © 
bath for heavy shades is prepared cold with 4 per cent of sodium 
nitrite and 10 per cent of concentrated hydrochloric acid. For 
light shades a bath of half this strength is sufficient. The im- 
pregnated acetate silk is treated cold, worked well, rinsed, and 
developed immediately. 

Phenol, resorcinol, a- and B-naphthol, Developer BON and 
Oxamine Developer B are recommended for use with the Ace- 
dronoles. The phenol or resorcinol developing bath is prepared 
by dissolving the developer directly in hot water, without any other 
addition. The naphthols and Developer BON are first made into 
a paste with hot water and an equal quantity of 38 or 40° Be. so- 
dium hydroxide solution, and this paste dissolved by adding hot 
water. Oxamine Developer B is dissolved in hot water by the 
addition of a little hydrochloric acid. 

Method No. 61-B: Developing the Acedronoles. The rinsed 
acetate silk, fresh from the -diazotizing bath, is entered into the 
_cold developing bath, except in the case of Developer BON which 
is used at 60 to 70° C. (140 to 158° F.) instead of cold, and 
worked for about a half hour. In using Developer BON, 2 to 4 
cubic centimeters of 6° Be. acetic acid, per liter of developing 
bath, must be added so as to give the liquor an acid reaction to 
litmus paper. After development the goods should be rinsed well 
and may be scrooped in the usual manner. A warm soaping in a 
bath containing 2 or 3 grams per liter of olive oil soap will in- 
crease the luster of the rayon. 


234 ACETATE SILK 


TABLE XXXVI 
Tue ACEDRONOLES ON ACETATE SILK 


Formula 
No. Color Base Developer 
X1 Yellow 1% Acedronole AB 1.5% phenol 
X2  Reddish-orange 1% Acedronole AB 1.5% resorcinol 
X3 Orange-red 1% Acedronole AB 1.5% B-naphthol 
X4 Henna 1% Acedronole AB 1.5% a-naphthol 
X5 Cardinal 0.7% Acedronole AB 3% Developer BON 
X6 Darkcardinal 1% Acedronole AB 1S Develop- 
er 
X7 Brown 1% Acedronole ND with 
5% sodium acetate 1% resorcinol 
X8 Darker brown 1.5% Acedronole DN with 
6% sodium acetate 1.5% resorcinol 
X9 Orange scarlet 2% Acedronole CA with 
6% sodium acetate 1.5% resorcinol 
X10 Bright scarlet 1% Acedronole CA with 
4% sodium acetate 2% Developer BON 
X11 Darker scarlet 1.5% Acedronole CA with 
6% sodium acetate 3% developer BON 
X12 Orange 1.25% Acedronole BN with 
6% sodium acetate 1.5% resorcinol 
X13 Dark orange 1.25% Acedronole BN with 
6% sodium acetate 1.5% B-naphthol 
X14 Orange brown 1% Acedronole AN with 
6% sodium acetate 1.5% phenol 
X15 Darker than 1.5% Acedronole AN with 
X14 8% sodium acetate 1.5% phenol 
X16 Brown, reddish 1% Acedronole AN with 
6% sodium acetate 1.5% a-naphthol 
X17 Darker than 1.5% Acedronole AN with 
X16 8% sodium acetate 2% a-naphthol 
X18 Darker than 1% Acedronole AN with 
X17 6% sodium acetate 1.5% resorcinol 
X19 Darker than 1.5% Acedronole AN with 
X18 8% sodium acetate 2% resorcinol 
X20 Darker than 1% Acedronole AN with 
X19(VeryDark) 6% sodium acetate 1.5% B-naphthol 
X21 Deep Blue 1% Acedronole AN with 
6% sodium acetate 2.5% Developer BON 
X22 Black 3% Acedronole AN with 
10% sodium acetate 5% Developer BON 
X23 Yellow 1% Acedronole AT 1.5% phenol 
X24 Reddish-tan 1% Acedronole AT 1.5% resorcinol 
X25 Bright Red 1% Acedronole AT 1.5% B-naphthol 
X26 Darker and 1% Acedronole AT 1.5% a-naphthol 
Browner than X4 
X27 Cerese 1% Acedronole AT is Re 2 Develop- 
er 
X28 Dark Cerese 0.7% Acedronole AT 3% Developer BON 


Se eee eee 


Formula 


No. 
X29 


X30 
X31 
X32 
X33 
X34 
X35 
X36 
X37 
X38 
X39 
X40 
X41 
X42 
X43 


X44 


Color 
Medium blue 


Darker than 
X29 


Darker than 
X21 or X30 


Blue-black 
Black 
Bright light 


yellow 


Lighter than 
X24 


Red henna 
Darker than 
X27 
Lavender Blue 
Darker than 


X38 


Slightly darker 
than X34 


Dark Red 
Red brown or 
dark henna 

Dark tan 


Darker than 
X43 


oe eolAL COMPONENTS 


TABLE XXXVI 


Base 


1% Acedronole DA 30% 
paste with 2% sodium 
acetate 

1.5% Acedronole DA 30% 
paste with 4% sodium 
acetate 

2% Acedronole DA 30% 
paste with 6% sodium 
acetate 

6% Acedronole DA 30% 
paste with 10% sodium 
acetate 

6% Acedronole DA 30% 
paste with 10% sodium 
acetate 

2% Acedronole B 30% 
paste with 4% sodium 
acetate 

2% Acedronole B 30% 
paste with 4% sodium 
acetate 

4.5% Acedronole B 30% 
paste with 6% sodium 
acetate 

6% Acedronole B 30% 
paste with 6% sodium 
acetate 

2% Acedronole B 30% 
paste with 4% sodium 
acetate 

3% Acedronole B 30% 
paste with 6% sodium 
acetate 

2.5% Acedronole T 30% 
paste with 5% sodium 
acetate 

4% Acedronole T 30% 
paste with 6% sodium 
acetate 

3.5% Acedronole T 30% 
paste with 6% sodium 
acetate 

1% Acedronole BN and 
0.4% Acedronole ND 
with 6% sodium acetate 

0.5% Acedronole AN and 

0.2% Acedronole BN with 
3% sodium acetate 


THE ACEDRONOLES ON ACETATE SILK 


Developer 


2% Developer BON 


2.5% Developer BON 


3% Developer BON 


5% Developer BON 


1% phenol 


1.5% phenol 


1% resorcinol 


1.5% resorcinol 


2% B-naphthol 


2.5% Developer BON 


3% Developer BON 


1.5% phenol 


2% B-naphthol 


1.5% resorcinol 


1.5% resorcinol 


1% resorcinol 


236 ACETATE SILK 


The Acedronole colors usually have a good fastness to water, 
washing, dilute organic acids, ironing, and with the exception of 
formulas No. X6, No. X12, No. X13, No. X87, and No. X41, a 
good fastness to light. They will withstand cross-dyeing in an 
acid bath (wool), with the exception of formulas No. X2, No. X3, 
No. X5, No. X9, No. X10, No. X11, No. X18, No. X19, No. 
X20, No. X24, No. X25, No. X28, No. X34, No. X35, No. X36, 
and No. X37. 

Where it is desired to dye the other fiber combined with the 
acetate silk, as in unions, the acetate silk should be dyed first ac- 
cording to Methods No. 61, No. 61-A, and No. 61-B, The cotton 
is then dyed with such substantive dyes as do not stain acetate 
silk, at about 40 to 60° C. (104 to 140° F.), or at a maximum of 
BOCs LTO cain) s 


The Acetylines 


The Acetylines of the Société Anonyme des Matiers Colorantes 
et Produits Chimiques belong to the developed class also. They 
are applied by Method No. 62. Acetylines SA, SB, SH, and 
SR give direct shades varying from yellow to orange, and Acety- 
line SP gives a direct brown, as shown in Table XXXVII. The 
Acetylines may be diazotized on the fiber and developed by Meth- 
ods No. 62-A and No. 62-B. The acetate silk should not be al- 


lowed to remain any longer than necessary in the acid Acetyline 


bath as acid solutions hydrolyze cellulose acetate to some extent. 

Method No. 62: The Acetylines on Acetate Silk. The dye bath 
should be prepared by mixing the Acetyline with half its weight 
of 20° Be. hydrochloric acid. This paste is dissolved in boiling 
water, using about 250 parts of water for each part of dye. If 
hard water is used, it should be slightly acidified with acetic acid. 
Before entering this bath the acetate silk should be thoroughly 
wet-out by working for about 5 minutes in a bath containing 95 
per cent of ammonia, on the weight of the goods. It is then rinsed 
with water and finally neutralized with water containing acetic 
acid. This wet-out silk is then entered at about 15° C. (59° F.) 
into the 30 to 1 dye bath containing the Acetyline, and the tem- 


ee ee eee 


a . , , ; 
Ee eS ee ee se nS Lae Te ee 


SPECIAL COMPONENTS 237 


perature of the bath gradually raised to 50° C. (122° F.) for 
about 30 minutes. 

Method No. 62-A: Diazotizing the Acetylines. The acetate silk 
from the above bath should be rinsed and diazotized at a tempera- 
ture below 15° C. (59° F.) in a 30 to 1 bath containing 2 to 5 per 
cent of sodium nitrite and 5 to 10 per cent of 20° Be. hydrochloric 
acid. In the case of Acetyline SD, the direct color of the Acetyline 
on the acetate silk must be entirely decolorized in the diazotizing 
bath. In case this does not occur in the above bath, it must be 
given a longer or stronger treatment, until the direct color is dis- 
charged. 

Method No. 62-B: Developing the Acetylines. The diazotized 
acetate silk should be rinsed quickly in cold water and entered into 
the developing bath without delay. A 30 to 1 developing bath 
is used containing 1 to 5 per cent of the desired developer and 
1 to 2 per cent of acetic acid. The acetate silk is entered at 15° 
C. (59° F.) and the temperature gradually raised to 50° C. 
(122° F.), while working for about 45 minutes. After develop- 
ing, the acetate silk should be rinsed well, brightened, and dyed. 

Developers MA and MC are dissolved in boiling water, without 
any other addition. Developers MB and MP should be mixed 
with an equal weight of 30° Be. sodium hydroxide solution, and 
then dissolved in boiling water. However the developing bath 
should be neutralized with acetic acid before entering the acetate 
silk. Developer ME is pasted with half its weight of sodium car- 
bonate, dissolved in boiling water and then neutralized as above. 
Developer ML is mixed with an equal weight of 20° Be. hydro- 
chloric acid, and then dissolved in boiling water. 

As most of the Acetylines do not stain other fibers they may be 
used for two colored effects on unions containing acetate silk. The 
Acetylines may be mixed in the dye bath, and the developers may 
_ be combined with each other in the developing bath to get a wider 
range of colors. Also the diazotized and developed colors may be 
“topped” with the direct Acetylines. This is particularly useful 
for greens and certain blacks. Table XX XVII gives the colors 
obtained direct and by development, and Table XXXVIII the 
amounts used to obtain various colors. 


ACETATE SILK 


238 


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asuelO aBULIQ BULIO-YSIPPey  MOT[P9A edULIO esuerIQ «= MOTPA VSULIO WS 
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UMOIg -YSIPpoy poyz-ysinig perw asue1() IBULIO-YSIPpey  IaULIO Usp[OH MOT[9 A -YSIuaeI+) WS 
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SUHIOTAAAG SAOIUVA AHL HLIM GNV LOAUIC ‘SANITALAIY AHL WOUd GANIVLAD SHOTO) 
IIAXXX ATAVL 


SPECIAL COMPONENTS 239 


TABLE XXXVIII 
AMOUNTS OF ACETYLINES AND DEVELOPERS USED 


Color Per Cent Acetyline Per Cent Developer 
Orange-Red 3% SA 2% MB 
Deep Orange 3% SA 295 MG 
Bluish-Red 3% SA 2% ML 
Poncean Red CL Bel 8! 2% MB 
Bluish-Red SA ats) 2% ME 
Bluish-Red 2 ee 2% ML 
Reddish-Brown Dele oe @ 295 ee 
Violet 2057 25 2% ME 
Violet Brown O96 SF Doe NG 
Yellowish-Orange 3% SH 2% MC 
Pure Blue 2p oD 1.5% ME 
Violet Blue Deo) Ce NL 
Greenish-Black 2095 2k VLE: 
Greenish 0.2% SD 1.5% ME, topped with 3% SA 
Bluish-Black Dogs) LD 5% ME, topped with 3% SA 


The Azgoniles 


The Azoniles of Meister, Lucius, and Bruning are another 
variety of products for development on acetate silk. Some of 
these stain the fiber directly, while others leave it colorless until 
developed. The manufacturers recommend only B-naphthol, re- 
sorcinol and Dianil Developer O for use upon the Azoniles but 
probably some of the other developers mentioned previously may 
be applicable in some cases to give additional shades. 

The Azoniles are dissolved for use by mixing into a paste with 
the necessary quantity of concentrated hydrochloric acid (see 
Table XX XIX below), adding 100 parts of boiling water to each 
part of dye, and finally heating to the boil if necessary. Actual 
boiling of the solution should be avoided in the case of Azonile R, 
which should simply be made into a paste with the acid, the water 
added at 90° C. (195° F.) and allowed to stand for 15 minutes 
at this temperature. Clear solutions will be obtained with Azonile 
N and SR, which may be stained into the lukewarm dye bath 
direct. In a 1:100 dilution Azonile N tends to precipitate on 
cooling, therefore the solution should be very hot when adding it 
to the dye bath. Azoniles G, R and B leave some residue when 
dissolving, therefore particular care should be exercised in filter- 
ing them. 


240 ACETATE SIRE: 


TABLE XXXIX 
AMOUNT OF HyprocHLoric ACID REQUIRED TO DISSOLVE THE AZONILES 


To Each 100 Parts of Use Hydrochloric Acid 
Azonile B 60 Parts 
Azonile G 70 Parts 
Azonile N 60 Parts 
Azonile R 100 Parts 
Azonile SR 60 Parts 


Method No. 63: The Azoniles on Acetate Silk. The scoured 
goods are entered into a lukewarm 30 or 40 to 1 dye bath, work- 
ing well and gradually adding during the dyeing from 10 to 20 
per cent of ammonium acetate, in solution, to aid exhaustion. In 
the case of Azoniles G, R and B, the ammonium acetate should 
be added very gradually in order to prevent precipitation of the 
Azonile. The temperature is raised during a half-hour to 60 or 
70° C. (140 to 160° F.) and the dyeing continued for a half-hour 
at this temperature, when the bath is usually exhausted. 

Method No. 63-A: Diazotizing of the Agoniles. The thoroughly 
rinsed goods are diazotized in a cold 20 to 1 bath for 30 minutes, 
containing 2 to 5 per cent of sodium nitrite and 4 to 10 per cent 
of concentrated hydrochloric acid, on the weight of the goods, de- 
pending upon the depth of shade. They are then rinsed well and 
should be immediately developed. In case a standing bath is used 
for diazotizing, it should be replenished after each run with about 
one-third the original quantity of acid and nitrite. The same pro- 
portion of developer should be added to the developing bath if a 
standing bath is used. 

The developers are dissolved in hot water. In the case of B- 
naphthol, the developer is pasted with 70 parts of 77° Tw. sodium 
hydroxide solution per 100 parts of naphthol, before adding the 
water. Thirty parts of soda ash are used in the same manner with 
each 100 parts of Dianil Developer O. 

Method No. 63-B: Developing the Azgoniles. The 20 to 1 devel- 
oping bath is prepared with 2 to 6 per cent of developer, on the 
weight of the goods, according to the depth of shade. The goods 
are entered cold and the bath slowly heated to 49° C. (120° F.), 
working the goods for about 45 minutes. After developing, the 


SPECIAL COMPONENTS 241 


acetate silk is rinsed well, hydroextracted and dried at not over 
49° C. The brilliancy of the color is increased by a light soaping 
before drying. 

The Azoniles give good full shades of excellent fastness to 
water, and with the exception of Azonile R which turns somewhat 
yellow, to washing. Azonile G, even when not diazotized and de- 
veloped, has very good fastness properties. With the exception of 
Azonile R developed with B-naphthol, and particularly Azonile B 
with Dianil Developer O, all of the Azoniles are very fast to light. 
Table XL gives a few of the colors obtainable. 


ABLE XL 
CoLors OBTAINABLE WITH THE AZONILES AND VARIOUS DEVELOPERS 

Color Azonile Developer 
Yellow G None, dyed direct 
Scarlet G B-napthol 
Dull Yellow N Resorcinal 
Orange R Resorcinol 
Cerise R B-naphthol 
Violet R Developer O 
Bright Blue B Developer O 
Reddish-Brown SR Resorcinol 
Navy Blue ike Developer O 


Black SR Developer O 


They may readily be used for two color effects on «unions of 
acetate silk with cotton or/and other rayons, by first applying the 
Azoniles as described above, which only stain the cotton faintly, 
and afterwards cross-dyeing at 60 to 70° C. (140 to 160° F.) in 
a salt bath containing no soap or alkalies with direct cotton colors 
which do not appreciably stain acetate silk. 


The Azgonines 


The Azonines are the product of the Cassella Company and 
are applied in two ways, according to Methods No. 64 and No. 65. 
As a rule they do not stain the cotton of acetate silk-cotton unions, 
and are therefore useful for two colored effects on goods of this 
class. Azonine G is directly soluble in boiling water without any 
addition. The other members of this group either require the 
addition of hydrochloric acid to bring them into solution, as is 


242 ACH TATE Sti 


the case with most bases of this class, or they may be applied with 
the aid of Tetralin or a similar solvent which is soluble in an aque- 
ous soapy dye bath. This latter method probably belongs with 
the dispersol methods of dyeing. Azonines R, 2R and S may be 
mixed in any proportions and give direct shades of yellow to 
orange without development. Azonine G also gives a direct shade 
and is never developed. All of the other Azonines may be de- 
veloped. Azonine B is colorless until developed. Table XLII 
gives a list of the colors obtainable. Azonine 2R may be amino- 
azotoluene. 

Also see Azonine SF which is best applied by dispersol methods 
and is discussed with the Direct Azonines under the Dispersol 
Dyes. It may also be applied in a formic acid bath, and in either 
case is diazotized and developed on the fiber. In using formic 
acid, the Azonine is pasted with twice its weight of 85 per cent 
formic acid and then dissolved in hot water. The material is 
entered into this bath, without any other addition and dyed for 
about 45 minutes at 70 to 75° C. (157 to 167° F.). 

Method No. 64: The Azonines on Acetate Silk. When applied 
by the acid method, Azonines B, R, 2R and S are dissolved in 
about 100 times their weight of water and the particular quantity 
of hydrochloric acid given in Table XLI. This solution, or the 
aqueous solution of Azonine G, is strained into the 30 or 40 to 1 
dye bath at 60° C. (140° F.). The scoured material is entered 
and worked for 45 minutes at 60 to 70° C. (140 to 160° F.). In 
the case of Azonine G, it is necessary to add from 3 to 10 per cent 
of acetic acid to the bath to aid exhaustion, and a standing bath 
may be used to advantage. In dyeing light shades or where there 
is trouble in leveling, the addition of a little hydrochloric acid to 
the dye bath, say 0.2 to 0.5 per cent on the weight of the goods, 
may be advantageous. 


TABLE XLI 
Amount or HypROcHLORIC ACID REQUIRED TO DISSOLVE THE AZONINES 
For Each Pound of Use Hydrocholric Acid 
Azonine B 9.5 ounces 
Azonine R 16. ounces 
Azonine 2R 13. ounces 


Azonine S 9.5 ounces 


a  — — — — 
———— sss eases 


oe ECIATL COMPONENTS 243 


Method No. 65: Azonines B, R, 2R, and S With Tetralin. One 
part of the Azonine dyestuff is made into a paste with three parts 
of tetralin, four and one-half parts of soap, and one-half part of 
soda ash. This paste is dissolved in 100 parts of boiling water 
and this solution is sieved into the dye bath after which the 
dyeing proceeds as in Method No. 64. While the dye exhausts 
from the bath very well, it may advantageously be used again on 
account of its tetralin and soap content. When this method is 
used on acetate silk-cotton unions, both fibers may be dyed in the 
one dye bath, in which case the salt is not added to the dye bath 
until twenty or thirty minutes after the goods are entered, by 
which time most of the Azonine will have been absorbed. 


TABLE XLII 

COLORS WITH THE AZONINES AND VARIOUS DEVELOPERS 

Color Per Cent Azonine Per Cent Developer 
Lemon Yellow (1) 4% G Direct, never developed 
Golden Yellow (2) 2%. 2% Phenol 
Reddish-Brown (3) 2% FR 2% Resorcinol 
Bright Scarlet (4) De 2% B-Naphthol 
Dark Red (5) Zo ak 2% Developer ON 
Bright Yellow (6) ING ARS Direct, not developed 
Reddish-Brown (7) Ae IA a 2% Resorcinol 
Lighter than 3 
Scarlet (8) 2% 2K. 1% B-Naphthol 


Lighter than 4 
Scarlet (9) 


Redder than 4 29.  2R 2% B-Naphthol 
Deep Maroon (10) IMeiies T PAN 2% Developer ON 
Dark Blue (11) 1.5°%.D 3% Developer ON 
Light Brown (12) VS 1% Phenol 
Very Dark Purple (13) 152 5S 1% Resorcinol 
Purple (14) be os) 1% Resorcinol 

Darker and bluer than 13 
Gray Blue 072% '5 1% Developer ON 
Black 3G. oS 3% Developer ON 


Method No. 64-A: Diazotizing the Azgonines. The Azonines, 
with the exception of Azonine G, may be diazotized on the fiber 
in a cold bath containing 2 to 4 per cent of sodium nitrite and 
5 to 10 per cent of 34° Tw. hydrochloric acid, according to the 
depth of shade, for 15 or 20 minutes. If preferred, less acid may 
be used and a little longer time given, for instance 5 or 10: per cent 


244 ACETATE Sil 


of 21° Tw. hydrochloric acid may be used cold for 30 minutes, 
instead of the above. After diazotizing rinse well and develop 
immediately. 

The developers are prepared by dissolving the phenol or re- 
sorcinol in hot water. One part of B-naphthol is boiled with 2 
parts of Turkey-red oil and 20 to 30 parts of water. Developer 
ON, which is possibly B-hydroxynaphthoic acid, is dissolved by 
boiling with 2 parts of sodium acetate and 20 to 30 parts of water. 
These solutions are added directly to the developing bath. 

Method No. 64-B: Developing the Azonines. The color is de- 
veloped with from 1 to 8 per cent of developer for 20 to 30 min- 
utes at 45 to 60° C. (115 to 140° F.). Azonine B requires about 
twice as much developer as the other Azonines. The goods should 
be rinsed and the shades may be brightened by a light soaping. 


The Azoles 


The Azoles of the Actien-Gesellschaft fur Anilin-Fabrikation 
are another brand of developed dyestuffs. Azoles AG, AR and 
AZ give direct shades which are fast enough for some purposes. 
Azoles 6GL and R also give direct shades but these are not very 
fast and should be developed. Azoles AG, AR, AZ, CB, and GL 
are particularly fast to light. 

Azole 6GL is soluble in hot water without any addition, but the 
others are brought into solution by means of the quantity of 
hydrochloric acid shown in Table XLIII and 100 times their 
weight of boiling water. They may be mixed indiscriminately in 
the dye bath. 

The developers recommended are phenol, resorcinol, B-naph- 
thol and Azole Developer ON. The colors developed with phenol 
are too sensitive to alkalies to be of practical value, but when the 
phenol is combined with other developers, useful shades are ob- 
tained. The shades developed with B-naphthol are not as fast 
to light as those obtained with resorcinol or Azole Developer ON. 
The Azoles have no affinity for cotton or the regenerated rayons 
and are therefore useful in unions where it is desired to leave 
the cotton white, or dye it in contrasting shades with direct cotton 
dyes. Table XLIV gives a list of the colors obtained direct and 
with various developers. 


SPECIAL COMPONENTS 245 


TABLE XLIII 
AMOUNT OF HypRocHLoric AcID REQUIRED TO DISSOLVE THE AZOLES 


Each 100 parts of Azole Requires Hydrochloric Acid 
AG 116 Parts 
AR 116 Parts 
AZ 174 Parts 
B ) 87 Parts 
D 87. Parts 
R 87 Parts 
sk 87 Parts 
CB 58 Parts 


Method No. 66: The Azoles on Acetate Silk. The scoured 
goods are usually dyed at 55 to 65° C. (130 to 150° F.) in a 30 
or 50 to 1 slightly acid dye bath for about an hour. For light 
shades or to aid leveling, 0.2 to 0.5 per cent of hydrochloric acid, 
on the weight of the goods, may be added to the dye bath, before 
sieving in the acid Azole solution. In applying heavy shades 
3 to 5 per cent, on the weight of the goods, of sodium acetate crys- 
tals, in solution, may be added to the dye bath about a half-hour 
after entering the goods, to aid the exhaustion. They are then 
dyed for another half hour and rinsed. 

Method No. 66-A: Diazotizing the Azoles. The dyed goods 
may be diazotized in a 20 or 30 to 1-bath with 3 to 6 per cent of 
sodium nitrite and 7 to 20 per cent of hydrochloric acid. They 
are rinsed cold and developed immediately. 

Phenol, resorcinol and B-naphthol are dissolved as described 
for the Azonines. Azole Developer ON, which is probably B- 
hydroxynaphthoic acid, is dissolved in 2 parts of sodium acetate 
crystals and 20 to 30 parts of water. The Developers may be 
mixed in the same bath as desired. 

Method No. 66-B: Developing the Azoles. Develop the diazo- 
tized material for a half to three-quarters of an hour at 45 to 60° 
C. (115 to 140° F.) in a 20 or 30 to 1 dye bath containing 2 to 
6 per cent of developer, on the weight of the goods. Azoles B, CB, 
D, and T require more developer, in proportion, than the other 
Azoles. After developing, rinse, soap, rinse, acidulate with acetic 
or tartaric acid, hydroextract and dry at from 49 to 60° C. (120 
to 140° F.). Basic dyes may be used for topping if desired. 


ACETATE SIGs 


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SPECIAL: COMPONENTS 247 


The Silkons 


The Silkons of the Griesheim Elektron Company are another 
small group of products belonging to this class. It has been stated 
that Silkon B corresponds to Acedronole AB, while Silkons C 
and D correspond to Acedronoles CA and DA, respectively. 
Silkons B and T give direct shades without development, the 
former a bright yellow (2 per cent) and the latter a more lemon 
yellow (also 2 per cent). Undoubtedly they are organic bases 
such as aminoazobenzene, aminoazotoluene, etc. Silkon Developer 
BON is probably B-hydroxynaphthoic acid. 

When 2 per cent of Silkon B is diazotized and developed with 2 
per cent of Silkon Developer BON, a bright scarlet is obtained, 
while Silkon T gives an even darker shade under the same condi- 
tions. One-half of one per cent of Silkon D with 1.5 per cent of 
Silkon Developer BON gives a brilliant violet-blue; and 3 per 
cent of the same Silkon with 1 per cent of Chrysoidine, when 
diazotized and developed with 4 per cent of this developer, gives 
a good black. Two per cent of Silkon T, diazotized and developed 
with 2 per cent of resorcinol, gives an orange-red, while Silkon B 
gives a deeper red shade under the same conditions. With phenol, 
Silkon T gives a bright yellow similar to that obtained from Silkon 
B with the same developer. 

Method No. 67: The Silkons on Acetate Silk. The Silkons 
should be dissolved in boiling water with the assistance of hydro- 
chloric acid, as given in Table XLV and then filtered into the dye 
bath. The goods should be dyed for from three-quarters to one 
hour at 60 to 70° C. (140 to 158° F.). When dyeing light shades, 
0.1 to 0.4 per cent of hydrochloric acid in the dye bath aids in 
leveling. Rinse once in cold water. 


S TABLES XLY 
AMOUNT OF HyprocHLoric ACID REQUIRED TO DISSOLVE THE SILKONS 


Each Pound of Silkon Require Hydrochloric Acid 


B 0.9 Pound 
D 0.7 Pound 
48 0.8 Pound 


248 ACETATE SILK 


Method No. 67-A: Diazotizing the Silkons. Diazotize cold for 
20 minutes in a bath containing 1 to 4 per cent of sodium nitrite 
and 3 to 10 per cent of 32° Tw. hydrochloric acid according to 
the depth of shade. Rinse once, cold, and develop. 

Method No. 67-B: Developing the Silkons. Develop for 30 
minutes with 1 to 4 per cent of the desired developer, rinse and 
brighten the shades in a bath containing 1 to 3 per cent of formic 
acid, on the weight of the goods. 


Cellit Fast Yellow 2GN 


Cellit Fast Yellow 2GN of the Bayer Company gives a pure 
yellow directly when applied by Method No. 68 which may be 
diazotized and developed according to Methods No. 68-A and 
No. 68-B, to give shades ranging from orange to deep purple or 
violet. From 1.5 to 2.5 per cent of special Developers A, B, F, 
H, J, N, or Z are used, according to the color and depth of shade 
required. When the dyed acetate silk is to be cross dyed on half 
wool, Developers A, B, F, H, N, or Z are recommended; and for 
wool, Developers B, F, H, N, or Z. Developer J becomes lighter 
on wool. Table XLVI gives the colors obtained with 2.5 per cent 
of the various developers on a 1 per cent dyeing of Cellit Fast 
Yellow 2GN. 


TABLE XLVI 
CoLors OBTAINED BY DIAZOTIZING AND DEVELOPING CELLIT FAST 
YELLOW 2GN 
Direct without development Pure Yellow 
~ Developer A Scarlet 
Developer B Bluish violet 
Developer F Browner-Scarlet than A 
Developer H Reddish- Violet 
Developer J Orange-Yellow 
Developer N Bluer than H 
Developer Z Yellowish-Orange 


Method No. 68: Cellit Fast Yellow 2GN on Acetate Silk. Use 
a 80 to 1 dye bath containing 5 per cent of 30 per cent acetic 
acid and 20 to 30 per cent of sodium sulfate. Dye at 77° C. 
(170° F.) and rinse. 

Method No. 68-A: Diazotizing Cellit Fast Yellow 2GN. Diazo- 
tize with 3 or 4 per cent of sodium nitrite and 6 or 8 per cent of 
32° Tw. hydrochloric acid. 


oe eletaAl COMPONENTS 249 


Method No. 68-B: Developing Cellit Fast Yellow 2GN. De- 
velop for 30 minutes at 40 to 46° C. (105 to 115° F.) with the 
desired developers in suitable quantity. Most of the developers 
are soluble in water but in the case of Developer B, add hydro- 
chloric acid, drop by drop, until the milky color of the solution 
disappears. Developer N is dissolved by boiling with 60 times its 
weight of water containing twice as much sodium acetate as de- 
veloper. ; 

In the case of half-wool unions, the fibers other than acetate 
silk should be dyed in a neutral Glauber’s salt dye bath. Wool is 
dyed in the usual manner with neutral or acid dyes at a tempera- 
ture below 80° C. (176° F.). 


The S.R.A. Diago Solamines 


The S.R.A. Diazo Solamines of the British Celanese Company 
were among the first dispersol dyes to be offered for acetate silk. 
These Diazo Solamines were products suitable for diazotization 
and development on the fiber, but were applied by the dispersol 
method of dyeing which will be considered in Chapter XXI. With 
the advent of the S.R.A. dyes of the same company, which give 
a wide range of very fast colors directly without development, the 
Diazo Solamines were withdrawn from the market. Undoubtedly 
the present S.R.A. Blacks, which are diazotized and developed on 
the fiber, belong to the class of compounds now under discussion, 
but as they are applied by dispersol methods, they will be con- 
sidered with the other S.R.A. dyes. 


TABLE XLVII 


A COMPARISON OF THE VARIOUS METHODS OF DIAZOTIZATION 
RECOMMENDED FOR THE DIFFERENT PRODUCTS ON ACETATE SILK 


Volume of % Temp. Temp. 

Brand Bath Q% Niuirnte HCL f BE sal cl Time 
Acedronoles —— 20 5to10 cold cold —-~ 
Acetylines 30 to 1 2 to 5 5to10 below15 below 59 20 min. 
Azoniles 20 to 1 28035 4to10 cold cold 30 min. 
Azonines — 2 to 4 5 to 10 cold cold 20 min. 
Azoles 25 tou 3 to 6 7 to 20 cold cold — 
Silkons a 1to4 3to10 cold cold 20 min. 
Cellit a 3 to 4 6to8 -— —- > --- 


250 ACETATE SIL 


TABLE XLVIII 


A COMPARISON OF THE VARIOUS METHODS OF DEVELOPING 
THE Azo CoLors ON ACETATE SILK 


Brand Volume of Bath Temp.°C. Temp. °F. Time 

Acedronoles cold cold 30 min. 

Developer BON 60 to 70 140 to 158 30 min. 
Acetylines 30 to 1 15 to 50 59 to 122 45 min. 
Azoniles 20 to 1 cold to 49 cold to 120 45 min. 
Azonines 45 to 60 115 to 140 30 min. 
Azoles 25 to 1 45 to 60 115 to 140 45 min. 
Silkons — —-~ 30 min. 


Cellit a 40 to 46 105 to 115 30 min. 


Gripe R Xx VItT 
Swelling Agents or Solvents in Dyeing Acetate Silk 


WirHout doubt all of these solvent methods of dyeing acetate 
silk are now obsolete, but they are of interest in showing some of 
the early difficulties and work in connection with the dyeing of this 
fiber. Very probably they are the fore-runners of many of our 
present-day methods. Possibly the use of dyeing “assistants” is 
based upon these methods, and in fact it is difficult to determine 
to which class some of the patents belong except from the amount 
of adjunct material used. It is interesting to note that the use of 
the various amines and phenols in dyeing acetate silk was first 
mentioned in this connection,? and that soap is also mentioned in 
connection with the solvents in the same patent. 

One of the first patented methods for dyeing acetate silk appears 
to be German Patent No. 193,135, July 5, 1905, to the Aktien 
Gesellschaft fur Anilin-Fabrikation. This process is also covered 
by British Patent No. 1931, January 25, 1906, to C. D. Abel, which 
states that acetate silk, which cannot be dyed in either an aqueous 
or alcoholic solution of Methylene Blue, may be dyed in a bath 
containing both of these solvents. Undoubtedly the acetate silk 
referred to in this patent consisted of the early primary type of 
cellulose acetate. 

For example, he states that 10 parts of acetate silk may be dyed 
in about 15 minutes in a bath containing 2 parts of Methylene Blue 
dissolved in a mixture of 200 parts of water and 150 parts of 
alcohol. Further examples cover the use of Magenta, Naphthol 
Yellow S, Erika B, Ponceau 4GB, and Chrysoidine, in amounts 
varying from 20 to 50 per cent on the weight of the fiber. Me- 
thanol, acetone, acetic acid or other suitable solvents that are 
miscible with water, and in which the dye is soluble, may be sub- 
stituted for the ethyl alcohol. Aniline in aqueous solution is also 
mentioned, and dyes of the basic, anthracene, and vat classes are 
suggested for use by this method. 


“United States Patent No. 961,241 and related patents. 
251 


252 ACETATE-SiICx 


French Patent No. 362,721, January 26, 1906, to the same 
inventor appears to cover a similar process. This proposes to pass 
the material through a bath containing the dye, organic solvent and 
water. For instance, 0.2 parts of Fuchsine is dissolved in 50 parts - 
of water and 50 parts of acetone. About 2 parts of acetate silk are 
worked in this bath for one-half to one hour, after which it is 
washed. One part of Naphthol Yellow S in 50 parts of water 
and 50 parts of alcohol may be used, working the acetate silk for 
one hour at 70° C. (158° F.). 

French Patent No. 383,636, November 6, 1907; German Patent 
No. 199,559, February 19, 1907; British Patent No. 24,284, No- — 
vember 2, 1907; and United States Patent No. 961,241, June 14, 
1910, to Knoll and Company, cover the use of organic solvents in 
dyeing acetate silk. They state that if the fiber is soaked for some 
time in solutions of the various organic substances, such as 50 per 
cent aqueous alcohol, or dilute acetic acid, at ordinary tempera- 
tures, the fiber swells and after hydroextracting, it may be dyed in 
the ordinary manner. They suggested the anthracene dyes as well 
as the basics and mention the fiber’s affinity for various amines 
and phenols or their derivatives. These patents give a good de- 
scription of the development of the azo colors on the acetate silk 
fiber, which is discussed in Chapters XVI and XVII, and also 
mention the use of glacial acetic acid, alcohols, ether, soap, etc., as 
solvents. 

In an addition to the above French Patent (No. 383,636), dated 
April 5, 1909, the use of inorganic acids, such as hydrochloric acid, 
in place of the organic substances or their solutions, as mentioned 
in the principal patent, for treating the acetate silk prior to or 
during the dyeing, is covered. The inventors state that this acid 
treatment has the effect of swelling the fiber and increasing its 
elasticity without any appreciable hydrolytic dissociation. How- 
ever this latter statement is rather doubtful, as cellulose acetate is 
hydrolyzed in an acid solution rather rapidly. British Patent No. 
743, March 31, 1909, covers this addition to the original patent. 

United States Patent No. 981,574, January 10, 1911, to E. 
Knoevenagel covers the use of hydrochloric acid in the dyeing of 
acetate silk, and also mentions hydrobromic, nitric, and sulfuric 
acids for the same purpose. 


SWELLING AGENTS 253 


The dyeing of fibers and other forms of the fatty acid esters of 
cellulose, such as cellulose acetate, was covered by the Furst Guido 
Donnersmarch’sche Kunstseiden-u. Acetatwerke in German Pat- 
ent No. 228,867, March 15, 1907. They state that the water- 
repellant nature of the esters may be overcome by the addition of 
acetin or other organic acid esters of glycerol, glycol, or their 
derivatives or homologues, to the dye bath. In this case, the shade 
varies with the quantity of the solvent preparation added. In the 
same manner, if the solvent preparation is added to the cellulose 
ester during the process of manufacture, before spinning in the 
usual manner, the resulting products may be dyed with aqueous 
solutions of dyestuffs in the usual manner. Also see United States 
Patent No. 1,532,427, which covers a somewhat similar but later 
process; and British Patent No. 244,143 on printing dispersol 
dyes. 

Knoevenagel! states that while cellulose triacetate is insoluble in 
water and only very slightly soluble in most organic liquids, it 
swells in many mixtures of organic liquids and in aqueous solutions 
of organic and some inorganic substances. These swollen acetates 
absorb dyes with a speed roughly proportional to the degree of 
swelling, and the amount of absorption which would require 
months with the original acetate, is effected in a few minutes with 
the swollen product. Not only dyes are absorbed by the swollen 
acetate, but also other organic and even inorganic substances. 

A factor which appears to have been overlooked in connection 
with these products is that according to some of these so-called 
solvent dyeing methods, it is possible to produce a partial surface 
hydrolysis of the primary cellulose acetate constituting the older 
acetates silks, to the later secondary acetone soluble variety, similar 
to that covered by the Miles patent. This applies particularly to 
the processes using mineral acids, previous to or during the dyeing, 
although the same result might be obtained to a smaller extent in 
aqueous solutions of acetic acid or acetone and especially alcohol 
or aniline. As these patents were all issued after Miles had ap- 
plied for his patent, at least some of the inventors may not have 
overlooked this point. 


Reference 
1E. Knoevenagel, Z. angew. Chem. 24, 504-5 (1911). 


CHAPTER XIX 
DYEING ACETATE SILK BY SAPONIFICATION 


The Saponification Process and Patents, and Methods of Dyeimg 
the Saponified Acetate Silk 


One of the first special methods for dyeing acetate silk was by 
the saponification, hydrolysis, or deacetylation process, wherein the 
cellulose acetate composing the fiber was treated with an alkaline 
solution, usually containing sodium hydroxide, sufficiently strong 
to saponify a certain portion of the cellulose acetate with a conse- 
quent replacement of some acetate radicles with hydroxyl groups, 
leaving a partially regenerated cellulose or hydrocellulose, some- 
what resembling a nitro silk. This method was possibly suggested 
by the denitration of nitrocellulose in the manufacture of the 
present nitro rayon, as well as by the Miles patent on the prepara- 
tion of cellulose acetate, as mentioned in Chapter XVIII. 

While the saponification process of dyeing acetate silk was never 
very successful nor widely used, it is of considerable interest in 
pointing out what may happen in case the acetate silk is not 
handled with extreme care in all alkaline solutions, such as in 
scouring, wetting-out, or dyeing. Very probably the process is not 
used at all at the present time, except in printing, and therefore 
the various patents will be considered rather briefly.* 

There were and still are a number of very serious objections to 
this method of dyeing acetate silk, yet almost every dyer, in first 
attempting to dye acetate silk, “discovers” this process during his 
early experiments and frequently spends considerable valuable 
time in trying to develop it. One of the principal objections to 
this method is the difficulty in obtaining level shades on a practical 
scale. Also the acetate silk loses in weight, as well as some of 
its most valuable properties, such as luster, strength, water resis- 
tance, etc., the amount of this loss depending upon the extent of 
the saponification. 


254 


: 
: 
: 
| 


eS 


DYEING BY SAPONIFICATION 255 


In this process the amount or depth of the regeneration or 
saponification depends upon the variety of alkali used in the solu- 
tion, the strength and temperature of the bath, and the length of 
time for which it is allowed to act on the fiber. This regenerated 
cellulose has dyeing properties resembling those of cotton or the 
other regenerated rayons, and it can therefore be dyed with direct 
cotton, sulfur, vat or basic dyes, either directly or with mordants, 
in the usual manner. Many variations and combinations of the 
saponification and dyeing processes are possible and were used, 
with more or less lack of success. For instance, in applying cer- 
tain dyes, the dyestuff itself may be placed in the saponifying bath, 
the dyeing and saponification proceeding concurrently. Salt may 
also be added to the alkali bath containing the dyestuff, to aid 
exhaustion, etc. 

A complete saponification of the cellulose acetate constituting 
acetate silk, with the resulting removal of all acetate groups, would 
very possibly yield a product with properties somewhat resembling 
a very inferior grade of ordinary nitro silk. Very probably it 
would not be as good in many ways as a properly prepared nitro 
or viscose silk, but we may expect it to dye in a similar manner, 
and the acetate silk would have lost all of its most valuable charac- 
teristic properties. On the other hand, a partial saponification 
may alter the properties, including the dyeing properties, of the 
acetate silk only to a limited extent, depending upon the extent of 
the saponification. 

Theoretically, a partial saponification can take place in three 
ways: (1) The alkali can penetrate and then saponify, the result 
being a general and uniform lowering of the acetyl value of the 
total esters; or (2) it may saponify immediately as it comes into 
contact with the surface of the fiber, before it penetrates into the 
interior. This of course results in a superficial coating of hydrated 
cellulose, graduating up to unmodified cellulose acetate in the in- 
terior. This result is obtained either by using a dilute caustic 
alkali solution at a high temperature, or by means of a stronger 
solution at a lower temperature. The other modification (3) is to 
use a certain definite quantity of caustic and allow it to act to 
complete exhaustion. In this manner a certain definite amount of 


256 ACE TAT ERasihr 


saponification is obtained and no more. Possibly 2 or 3 give the 
best results in practice. 

However, Haller and Ruperti? report that attempts to prepare a 
partially hydrolyzed acetate silk of low acetate content, by varying 
the conditions of hydrolysis, failed, the “partially hydrolyzed” 
products being fully hydrolyzed on the surface but unchanged at 
the core. They give photomicrographs to illustrate the swelling, 
optical, and dyeing properties of ordinary and hydrolyzed Celanese. 

In the saponification process, the reaction is most rapid during 
the first five minutes or so after the fiber is entered into the saponi- 
fying bath. This rapid action of course results in a rather sensi- 
tive process. The original unsaponified fiber has a certain amount 
of water resistance, which the saponified portion of it no longer 
possesses to the same extent. For this reason that portion of the 
fiber first attacked by the alkali rapidly absorbs more water con- 
taining alkali and is of course further hydrolyzed, with a resulting 
very uneven effect. 

The literature upon the hydrolysis or saponification of acetate 
silk has sometimes suggested that the acid and alkaline hydrolysis 
of acetate silk are similar but Mr. Mork* points out where this is 
in error and shows that there is a very positive difference between 
these two types of hydrolysis. For example, if Lustron is hydro- 
lyzed with a moderately weak solution of a mineral acid, such as 
nitric or hydrochloric acid, a gradually increasing affinity for the 
basic dyestuffs results without destroying the resistance of the fiber 
to direct dyestuffs until the hydrolysis has progressed to a very 


marked extent. On the other hand, a mild alkaline hydrolysis will 


give the Lustron an affinity for direct dyestuffs, before hydrolysis 
has progressed very far, and the elimination of only 10 per cent of 
the combined acetic acid will make the yarn dye faster than mer- 
cerized cotton with direct dyes. This indicates that at least in 
some instances the hydrolysis must proceed throughout the fiber 
and not entirely superficially. Also, Celanese, containing, say, 53 
to 55 per cent of combined acetic acid, will not dye with direct 
dyes, while Lustron hydrolyzed by alkali to the same acid content 
is readily dyed by the direct dyestuffs. 


*Private communication. 


DeeinG BY SAPONIFICATION 257 


Analysis of Saponified Acetate Silk 


As would be expected, the properties of the partially hydrolyzed 
acetate silk varies considerably with the extent of the saponifica- 
tion. The extent of the hydrolysis may be determined by analysis, 
in which the partially saponified fiber is repeatedly extracted with 
dry boiling acetone in a Soxhlet or other suitable ‘continuous ex- 
traction apparatus. This solvent removes only the unsaponified 
secondary cellulose acetate. In case the fiber contains primary 
cellulose acetate, which is unlikely in the present products, it 
should be extracted with chloroform instead of acetone, but in the 
same manner, and then extracted with acetone, as above. The in- 
soluble residue consists of regenerated cellulose and acetate so 
altered as to be insoluble in the acetone. The analysis may be 
carried further by extracting this residue 3 times for 2 minutes 
each with ten times its weight of cuprammonium reagent, which 
entirely removes the saponified cellulose, leaving only the partially | 
saponified cellulose acetate. The cuprammonium extract may be 
acidified and the precipitate washed, dried and weighed. 

While the saponification method of dyeing acetate silk was at 
one time rather widely advocated and numerous patents were 
granted upon various modifications and combinations of the proc- 
ess, it is not used at present in dyeing acetate silk and is no longer 
recommended. A very good reason for this is that with the many 
new and excellent dyes for this fiber now available, this always 
more or less unsatisfactory process is no longer needed. The 
saponification process which was formerly recommended by sev- 
eral companies is given in Method No. 69. While the original 
patent upon the saponification process for dyeing acetate silk was 
issued to Mr. H. S. Mork, of the Lustron Company, this particular 
method is covered by British Patent No. 169,741, April 29, 1920, 
to the British Cellulose and Chemical Manufacturing Company, 
and United States Patent No. 1,425,364, August 8, 1922, to Briggs, 
assigned to the American Cellulose and Chemical Company. 

Method No. 69: Saponifying Acetate Silk. Thoroughly scour 
the acetate silk as in Method No. 5 and enter 10 pounds of it into a 
100 gallon bath containing 3 pounds of 72° Tw. sodium hydroxide 
solution heated to 75° C. (167° F.). Hold the bath at this tem- 


258 AGE TAT He slr 


perature and work the goods for 45 minutes. Wash the material 
in warm water until free of alkali and sour in a dilute acetic acid 
solution. Rinse again, wash in soft water, and soap lightly. 
Where the goods are to be dyed immediately, the souring and 
subsequent operations may be omitted. 

This particular method is stated in the patent to apply especially 
to acetate silk containing 2 to 2.5 acetate groups per cellulose 
molecule, and temperatures of from 40 to 80° C. (104 to 176° F.) 
are mentioned as suitable. The quantity of alkali is restricted to 
that necessary to produce not more than a 10 per cent loss in 
weight in the acetate silk originally present. The above formula 
gives about this loss in weight. Sodium hydroxide or carbonate, 
or potassium hydroxide in not over one per cent concentration are 
mentioned as suitable alkalies. A provisional specification covers 
the saponification of any acetate lower than cellulose triacetate 
and states that the restricted saponification may also be affected by 
using an excess of reagent for only a limited time of action. It 


also refers to British Patent No. 158,340, covering the use of» 


ammonium thiocyanate. 

The best result which the author has seen along this line was 
obtained by the use of Mordant LB of the Liberty By-Products 
Company. Mr. Ernest A. F. Zillessen, working under Mr. Mork’s 
basic patents upon the saponification process of dyeing, developed 
this product, which consists of a special mixture of sodium car- 
bonate and a colloid. Zillessen found that on saponifying acetate 
silk by the usual process, i.e., in a bath containing about 10 grams 
of soda ash per liter at 85° C. (185° F.) for an hour, the addition 
of, say, 5 grams per liter of a suitable colloid, such as gelatin, 
casein, or glucose, to the bath, gave a much more level saponifica- 
tion with a minimum loss in weight by the fiber. In this way he 
is able to saponify Celanese sufficiently to apply the direct cotton 
dyes, as for instance Noil’s Direct Fast Scarlet B, in medium 
shades, with only a 3 per cent loss in weight of the acetate silk 
and only a very slight reduction in luster. While the process ap- 
pears to work very nicely on acetate silk effects, where solid colors 
are desired, it has not proven satisfactory on all Celanese piece 
goods, etc. Neither has it been used very extensively in skein dye- 


DYEING BY SAPONIFICATION 259 


ing, due to the loss in weight of the fiber. However, in many cases 
where the fastness of the direct colors are satisfactory, it is 
cheaper than the use of some of the special acetate silk dyestuffs. 


Saponification Process Patents 


As mentioned before, the first patented saponification process 
for dyeing acetate silk appears to be that covered by United States 
Pate On 061,771 (1913); French Patent No. 416,752, June 
4, 1910; and British Patent No. 20,672, September 5, 1910, to 
H. S. Mork of the Lustron Company. 

Cross and Dreyfus, in British Patent No. 125,153, June 19, 
1916, suggested the use of an ethyl or methyl alcoholic medium 
with a fractional equivalent of alkali or base so that the alcohol 
of the medium takes part in the subsequent saponification of the 
acetate. 

British Patent No. 150,989, May 17, 1920; and United States 
Patent No. 1,366,023, January 18,1921, to the Société Chimique 
des Usines du Rhone, anciennement Gillard, P. Monnet, et Cartier, 
covers the use of hot or cold solutions of metallic salts, to which 
alkali has been added, and mentions sodium chloride and hydrox- 
ide. 

British Patent No. 183,806, May 17, 1922, and United States 
Patent No. 1,440,501, January 2, 1923, to the same society, covers 
the partial saponification of acetate silk by means of trisodium 
phosphate, prior to or during dyeing. Swiss Patent No. 100,708 
to the Société pour la Fabrication de la Soie “Rhodiaseta” appears 
to cover the same process. 

British Patent No. 192,994, April 19, 1922, an addition to the 
above Patent No. 150,989 to the same inventors, covers the use of 
a neutral salt of an alkali metal, to which has been added, in the 
place of the alkali, as in the principal patent, a salt having an 
alkaline reaction and adapted to effect the desired saponification. 
For example: 100 grams of acetate silk may be soaked in a 2 liter 
bath containing 800 grams of sodium sulfate and 15 grams of 
trisodium phosphate for about 1 hour at 70 to 80° C. (158 to 176° 
F.), or until the solution fails to react alkaline. It is then washed 
and dyed. Sodium borate, silicate, and carbonate are also men- 
tioned. 


260 ACETATE SIGK 


Richardson in United States Patent No. 1,442,631, January 16, 
1923, and British Patent No. 176,034 of 1920, covered the use of 
sodium acetate in alkaline saponifying baths. British Patent No. 
175,486 of 1920 to the British Celanese Company covers the use of 
alkali silicates, aluminates, and borates in saponifying baths, the 
aim being to secure a more level effect. 

British Patent No. 193,912 and No. 194,244, November 2, 1921, 
to W. Bader and the British Cellulose and Chemical Manufactur- 
ing Company cover the partial saponification of acetate silk with a 
2 to 15 per cent solution of caustic soda, controlling the saponify- 
ing action by means of low temperatures; by adding alkali metal 
salts; or by the precipitation of insoluble soap films on the fiber. 
For example, the acetate silk may be saturated with a solution of 
soap and afterwards treated with brine, whereby the fibers be- 
come coated with a protective film of soap. They are then treated 
with a 10 per cent solution of caustic soda for 15 to 20 minutes. 
Or the acetate silk may be first treated with concentrated solutions 
of such salts as the chlorides of sodium, calcium, or magnesium, 
after which the saponification is claimed to be more regular. Small 
amounts of alkali or alkali-earth hydroxides may be added to the 
saline solution. This preliminary treatment has a specific action 
on the acetate silk, so that the superficial saponification effect can 
be obtained even when the salts employed have been completely 
washed out of the fiber. For example, acetate silk is soaked for 2 
hours in a 25 per cent solution of sodium chloride, or boiled for 
10 minutes in the solution. It is then saponified in a cold 5 per 
cent solution of sodium hydroxide. It is claimed that the dyeing 
properties are greatly improved, while the loss in weight is only 
Lor 2A°perscent: 

In British Patent No. 195,920, November 2, 1921, to Bader and 
the British Cellulose and Chemical Company, the partial saponifi- 
cation of acetate silk is effected in a cold one per cent caustic alkali 
solution, the action of which is accelerated by the presence of finely 
divided solids, either suspended in the saponifying bath or precipi- 
tated on the fiber. Clay, alumina or silicic acid gel, prepared so as 
to be insoluble in cold dilute alkali, may be added to the caustic 
solution, or the fiber may be treated in such a manner as to form 


DYEING BY SAPONIFICATION 261 


insoluble precipitates on it, such as calcium carbonate, magnesium 
oxide or carbonate, aluminum, or calcium oleate, etc. In a modi- 
fication, alkali aluminates are dissolved in the saponifying liquid 
and these deposit a colloidal hydrosol on the fiber. For example: 
acetate silk may be soaked for 2 hours in a 25 per cent solution of 
sodium chloride, then squeezed and suspended in a 40 to 1 solu- 
tion containing 30 per cent of aluminum sulfate, on the weight of 
the fiber, sufficient caustic soda to convert it into sodium aluminate 
(NaAlO2), and excess of caustic soda equal to 10 per cent of 
the weight of the acetate silk. Saponification is complete in about 
2 hours. 

According to British Patent No. 209,849, October 21, 1922, to 
the Badische Company, the alkaline saponification of acetate silk 
may take place in the presence of soluble aldehydes or hydroxy 
aldehydes, or their salts, or mixtures of the above aldehydes and 
acids. The process may be varied to give the fiber either an in- 
creased or decreased affinity for dyes. French Patent No. 558,900 
covers a similar process, in which it is claimed that neither the 
strength or luster of the acetate silk is impaired. The treatment 
may take place prior to or during the dyeing process. 

A recent French process of saponifying acetate silk is covered 
by French Patent No. 590,738, February 15, 1924, to Teinturerie 
de la Rize. In this process the fiber is treated for from 15 minutes 
to 2 hours at 50 to 70° C. (122 to 158° F.) with an aqueous solu- 
tion containing 1 kilogram each of barium hydroxide and barium 
chloride in each 100 liters of bath. 

United States Patent No. 1,489,814, April 8, 1924, to M. E. 
Bouvier covers the treatment of acetate silk in a concentrated solu- 
tion of neutral alkaline salts, containing not more than one per 
cent of an alkali salt capable of hydrolyzing the fiber. For ex- 
ample: Water 2 liters, sodium sulfate 350 grams, and sodium car- 
bonate 17 grams. 


Dyeing Saponified Acetate Silk 


The dyeing of saponified acetate silk proceeds in exactly the 
same manner as the dyeing of viscose rayon, except that tem- 
peratures below 75° C. (167° F.) should be used. The direct cot- 


262 ACETATE SIE 


ton, as well as the other dyes generally used on viscose, are very 


satisfactory for this purpose. When the sulfur dyes are to be 
used, they are generally applied in a combined saponifying and 
dyeing operation, using a strongly alkaline bath containing the 
alkali, sulfide, and dyestuff. Many other dyes may be applied 
concurrently also, particularly the vat dyes. However this com- 
bined saponifying and dyeing process is subject to the same crit- 
icisms as applied to the other saponification processes of dyeing. 

A combined saponification and dyeing process is covered by 
British Patent No. 178,946, January 27, 1921, to Briggs, Richard- 
son, and the British Cellulose and Chemical Manufacturing Com- 
pany. This process is given in Method No..70. British Patent 
No. 224,218, November 3, 1923, to the Société Alsacienne de 
Produits Chemiques covers another combined process. In this 
patent it is suggested to use a saponifying and mordanting bath 
containing sodium hydroxide or phosphate with a sulfurized com- 
pound of phenol” (Katanol) or its derivatives or substitution 
products. It is stated that the shades obtained with basic dyes 
are similar to those obtained on a tannin mordant and that the 
treatment with antimony salts is not necessary. The mordant 
may be used in the same bath with substantive or sulfur dyes, 
when these are to be topped with basics. 

Method No. 70: Combined Saponification and Dyeing of Ace- 


tate Silk-Cotton Unions. The union is worked in a dye bath con- 


taining small quantities of soap and/or soda ash at a temperature 
below 50° C. (122° F.) until the cotton is fully dyed, leaving the 
acetate silk slightly stained. The temperature of the bath is then 
raised to 75 or 80° C. (167 or 176° F.) and a small amount of 
alkali, that is up to 10 per cent of sodium hydroxide, on the 
weight of the acetate silk, is added. As the saponification pro- 
ceeds, the color bleeds from the cotton onto the acetate silk. It is 
claimed that by properly controlling the process, level shades may 
be obtained. Sodium carbonate, sulfide, silicate, aluminate, and 
borate, as well as the hydroxide, are suggested as saponifying 
agents. 

The following dyes have been particularly recommended for 


’See British Patent No. 215,012. 


a 


DYEING BY SAPONIFICATION 263 


the saponified acetate silk. Those starred have exceptional fast- 
ness to light. Chlorazol Fast Yellow B and Chlorazol Fast Red 
FG9202K are direct dyes which are not decomposed by sodium 
sulfide and may therefore be used in the same bath with sulfur 
dyes for shading. 


Chlorazol Fast Yellow NX Chlorazol Fast Red FG9202K 
Chlorazol Fast Orange D Thionol Corinth RBX 
*Chlorazol Fast Red K *Thionol Blue 2B 

Chlorazol Violet N Thionol Black Brown B9146K 
*Chlorazol Fast Blue 2B Thionol Black XXN conc. 
Chlorazol Sky Blue GW *Thionol Black OG 
*Chlorazol Green BN *Cross Dye Sky Blue FFS 
Chlorazol Dark Green PL *Cross Dye Green 2G Concentrated 
*Chlorazol Brown M Cross Dye Brown 2R 
Chlorazol Black E extra *Cross Dye Black BX 
Chlorazol Black BH Cross Dye Yellow Y 


*Chlorazol Fast Yellow B 


While the saponification process of dyeing acetate silk has been 
almost entirely superseded*® by the use of the many special dyes 
for acetate silk, it is still used in a few cases for printing, etc. 
At best, the process is extremely difficult to control on a large scale 
and on all classes of goods. In every case the fiber loses weight, 
and if the saponification is carried very far, it also shrinks, loses 
luster, strength, water resistance, and of course cross-dyeing prop- 
erties. However, a full understanding of the process is very im- 
portant to all dyers, as many of their troubles in handling acetate 
silk may be traced to a partial hydrolysis of the fiber in some pre- 
vious process, such as scouring. 


References 


1C, E. Mullin, American Dyestuff Reporter 14, 382 (1925). 
?R. Haller and A. Ruperti Leipzig Monato. go, 353 and 399 (1925). 
°B. Roetel, Textilber 7, 43-4 (1926). 


CHAPTER 
THE IONAMINES 


The Development of the First Special Dyestuffs for Acetate Silk. 
The Patents Covering Them. Their Application to, and Properties 
on, Acetate Silk. 


Tue fact that many compounds insoluble in water dye acetate 
silk, and that the usual method of solubilizing dyestuffs, that is by 
sulfonating, usually destroys the affinity of the product for acetate 
silk, led to research for a new method of solubilizing the insoluble 
bases, dyes, etc., without reducing their affinity for the acetate 
silk. Several methods of solubilizing without introducing the sul- 
fonic group have been mentioned, such as the introduction of the 
carboxyl and other acidic groups, etc., but the Ionamines are en- 
tirely new products, quite different from those mentioned, and are 
applied by an entirely new method. They were the first products 
developed to meet the exacting requirements of the acetate silk 
dyeing industry and are today one of the most important groups 
of dyes for this purpose. 

According to Green and Saunders,! various dyeing experiments 
on acetate silk led to the theory that dyestuffs containing hydroxy 
alkyl radicles attached to nitrogen might have an affinity for acetate 
silk by virtue of their alcoholic groups. However, the azo com- 
pounds of this type prepared, which included dihydroxyethyldi- 
aminoazobenzene, nitrobenzeneazodihydroxyethylaniline, and ben- 
zeneazobisdihydroxypropylaniline, were not highly successful. 
While the simpler bases which were soluble in water had an affinity 
for acetate silk, the affinity decreased as the number of alcoholic 
groups increased, thus disproving the hypothesis. 

It was then concluded that the dyeing of acetate silk was mainly 
a solution problem conditioned by the following factors: (1) The 
dye should contain amino, substituted amino, or hydroxyl groups ; 
and strong salt forming groups, such as the sulfonic group should 
be absent, or if present they greatly reduce or obviate the dyeing 
affinity. (2) When basic compounds are used as their salts with 


264 


THE IONAMINES 265 


acids, such as dyestuff-hydrochlorides, the salt should be readily 
dissociated by water, as it is the base and not the salt which is 
absorbed by the fiber. (3) The free base should be at least spar- 
ingly soluble in water. (4) As high molecular complexity tends 
to diminish solubility in non-aqueous solvents, such as acetate silk 
fiber, the molecule should not be too large. By the application of 
these rules (which in most respects parallel very closely those on 
which the S.R.A. dispersol dyes were later developed, as well as 
Clavel’s theory), after considerable research, compounds were 
produced which were more or less soluble in water, and which 
hydrolyzed in solution as desired, giving the sparingly soluble base 
of not too complex form to be absorbed by the acetate silk. 

The actual products eventually used are the omega-sulfonic 
acids of amino compounds of the general formula X.NR’.CHR”.- 
SO3H, in which X is a hydrocarbon nucleus, and R’ and R” are 
alkyl groups or hydrogen. While such compounds are not new? 
they had not previously been used commercially as dyes. The 
simpler compounds of this class, which are colorless, are formed 
by treating primary or secondary amines with aldehyde bisulfites, 
such as formaldehyde bisulfite, or formaldehyde and sodium bi- 
sulfite, as 
CeHs.N :N.CgH4.NHe. -|- HCOH a NaHSO, ——~»> 

CeHs5.N :N.CgH4.NH.CH2SO3Na. 
Aniline Yellow (Insoluble) Soluble Ionamine 


“The first patent covering an omega-sulfonic acid compound appears to 
be British Patent No. 11,343, May 31, 1899, to C. D. Abel for the Actienges. 
fur Anilinfabrikation. It states that by treating anhydroformaldehyde com- 
pounds of aromatic amines having the typical formula R.N:CHe with sul- 
furous acid or bisulfites, acids are obtained having the typical constitution 
R.NH.CH2SO:H, which are well characterized substances, and readily sol- 
uble in sodium carbonate solutions and in caustic alkalies. On combining 
them with suitable diazo compounds, and replacing the CHzSOsH group 
with hydrogen, by treating the azo compounds with alkalies, alkaline car- 
bonates, or mineral acids, mixed amidoazo compounds may be obtained. 
For example a mixture of 11.9 kilos of anhydroformaldehyde-o-toluidine 
and 60 kilos of 32° Be. sodium bisulfite solution are mixed until it solidifies 
as a mass of methyl-o-toluidine-omega-sulfonic acid. Or, the solution of 
p-nitrodiazobenzene chloride from 6.9 kilos of p-nitroaniline is added to a 
cold solution of 10.5 kilos of sodium methylaniline-omega-sulfonate and 
13.6 kilos of sodium sulfate in 50 liters of water . After filtering off the 
dyestuff, it is mixed to a paste with water and heated with 6 kilos of sodium 
hydroxide in 200 liters of water. Formaldehyde is given off, and, on acidu- 
lating, sulfurous acid is evolved. The reaction is complete after boiling for 
a half hour, when the dyestuff is filtered off and washed with water. 


266 ACETATE sick 


These omega-sulfonic compounds, while stable in neutral solu- 
tion, have the desired property of readily hydrolyzing on heating 
in the presence of dilute acids or alkalies, to give the corresponding 
amine or amino compound and the aldehyde bisulfite compound 
or its decomposition products, as follows: 

CsH;.N -N.CgH4.NH.CH2SO3Na + HGE ++ H2.O nero ca? 

CgHs.N :N.CgHa.NHe -|- HCOH + SOs -|- NaCl + H.O; and, 
C,H;.N -N.CgHy.NH.CH2SO3Na + NaOH —- H.2O — 
CeHs.N -N.CgH4NHo —- HeGe a. NaSOg3 -- H,O. 

While the base is nearly insoluble in water, it is soluble in acetate 
silk, and has the usual high affinity of the amino compounds for it. 
The readily hydrolyzable character of the Ionamines is due to the 
fact that the sulfonic group is situated externally to the nucleus 
of the dye proper. | 

Such azo dyes, depending entirely upon the omega-sulfonic acid 
groups for solubility, behave in general like acid dyes and the free 
aminoazo base dyes acetate silk, especially in a slightly acid or 
alkaline bath. This free base can in most cases be diazotized and 
coupled with phenols or amines on the fiber, as described in Chap- 
ters XVI and XVII. The products derived from primary amino 
compounds contain free amino groups and may be diazotized and 
developed, giving a wide range of fast colors. The products de- 
rived from secondary amino compounds may be used for direct 
shades but are not diazotizable. Methyl-omega-sulfonic acid com- 
pounds of aminoanthraquinone may be prepared in the same man- 
ner as these aminoazo compounds and are applied in the same man- 
ner. Probably some of these give direct shades of excellent fast- 
ness. These methyl-omega sulfonic acid compounds, while quite 
different from the sulfato acid dyes of Chapter XIV, which are 
very stable in acid or alkaline solution, form an interesting com- 
parison with them. 

These omega-sulfonic acid products are called Jonamines and 
are applied in slightly acid or alkaline dye baths at about 65 to 75° 
C. (140 to 167° F.). They have a good affinity for acetate silk 
and exhaust well even in dilute baths without the addition of salt. 
In the presence of sufficient acid they level well, if the temperature 
of the bath is not increased too rapidly. The dye bath should be 


- Se ay SS ee ee 


THE IONAMINES 267 


about 20 to 100 times the weight of the material. In dyeing cord 
or fabrics which require deep penetration, it is best to work the 
material well in a neutral dye bath and then acidify and warm the 
bath gradually during the dyeing. 

The Ionamines which have the greatest affinity for acetate silk 

have the least affinity for cotton, and those which have the greatest 
affinity for cotton have least for acetate silk. The other artificial 
silks react to the Ionamines in the same manner as cotton. Wool 
is dyed by the unhydrolyzed dye in an acid bath, but not by the 
free base after hydrolyzation, as is the acetate silk. 
_ The first Ionamines were divided into two classes: Those con- 
taining one salt forming group within the molecule, such as Iona- 
mine B; and those containing two salt forming groups, such as 
Ionamine A. The later nomenclature adopted for the Ionamines 
uses distinguishing letters only to denote those intended for devel- 
oping colors, while the direct dyeing Ionamines are denoted by 
the color produced. The Ionamines containing only one salt 
forming group have greater stability to hydrolysis and when dyed 
are not greatly affected in shade by organic acids. Those contain- 
ing two salt forming groups are more easily hydrolyzed and may be 
applied with formic or acetic acid, sodium carbonate, sodium ace- 
tate, or in a neutral bath. When dyed, the direct shade is easily 
affected by dilute organic acids, but when diazotized and developed 
they are fast and give deep shades. 

In diazotizing and developing Ionamines containing two free 
amino groups, care must be taken to insure complete tetrazoti- 
zation and coupling or the color will not be fast. Only the unsul- 
fonated phenols are useful in developing and B-naphthol, resorci- 
nol, or B-hydroxynaphthoic acid are particularly recommended. 
Sulfonated developers, such as R-salt, do not penetrate the fiber. 
Various combinations of these with the different Ionamines give 
a wide range of colors, very fast to washing, light, perspiration, 
rubbing, etc. 

In general, the light fastness of the colors developed with resor- 
cinol is usually better than with any other developer, while those 
developed with B-hydroxynaphthoic acid come next. The objec- 
tion to basic developers, such as m-phenylenediamine, is that they 


268 ACETATE SIEK 


may be taken up by the fiber in excess and later mark off on white 
material. This fault may possibly be overcome by using a suffi- 
ciently weak bath. Ethyl-B-naphthylamine gives violet to blue 
shades with several Ionamines but these colors are not fast to light. 
B-Hydroxynaphthoic acid is recommended for blue and black 
shades and it should be noted that when applied from a slightly 
acid solution, it gives deeper and faster shades, especially to light. 

Interesting two-color effects are obtained on cotton-acetate 
silk unions dyed either in one bath or by cross-dyeing. In dyeing 
wool-acetate silk unions, it must be remembered that the unhy- 
drolyzed dye acts as an acid dye on the wool and this must be 
taken into account. Natural silk is partly dyed by the hydrolyzed 
and partly by the unhydrolyzed dye. All this points to a wider use 
for the Ionamines than on acetate silk alone, owing to their com- 
bined acid and basic properties. 

The colors available vary from yellow and orange to scarlet, 
red, maroon, violet, blue, and black. However there does not yet 
appear to be any brown or direct black Ionamines. Cellutyl Union 
Black R is a mixture of a direct cotton black and an Ionamine in 
such proportions as to give a uniform black on cotton-acetate sill 
unions upon developing with B-hydroxynaphthoic acid. Recently 
special attention has been paid to the development of new Tona- 
mines containing only one salt forming group, similar to the 
original Ionamine B, as these dyes are of satisfactory fastness 
when dyed direct without diazotizing and'developing. It was par- 
ticularly difficult to find a fast blue, as the aminazo, disazo, and 
induline compounds tried were unsatisfactory. While the omega- 
sulfonic acid compounds of gallocyanine combined with paradia- 
mine gave reddish-blue to violet shades in neutral baths, they were 
not fast to light. The Ionamine Blue R and G eventually produced 
are the omega-sulfonates of unsulfonated aminoanthraquinones* 
and have excellent light fastness. These dye in the same manner 
as the other members of the group but do not exhaust as com- 
pletely. The difficulty described under Phototropy” was also en- 
countered in developing the Ionamines. 


“See British Patent No. 211,720. 
°See Chapter VIII. 


: 
| 


THE IONAMINES 269 


In practical dyeing some difficulties were experienced in ob- 
taining through penetration with Ionamines containing a very 
insoluble base, such as Ionamine A, but this was overcome by en- 
tering the material at about 30° C. (86° F.) in a dye bath con- 
taining 3 to 5 per cent of mineral acid and increasing the tempera- 
ture very slowly to about 75° C. (167° F.) and dyeing for about 
one-half hour or longer. In this manner the hydrolysis of the dye 
is retarded, allowing it to penetrate the material. As before stated, 
the Ionamines may be either primary or secondary, according to 
whether the amino group carrying the alkyl omega-sulfonic acid 
group is primary or secondary. Usually the secondary Ionamines 
have better penetrating qualities than the primary, and are there- 
fore more level dyeing. The two groups can readily be differen- 
tiated by the action of nitrous acid which decolorizes the second- 
ary Ionamines without forming a coupling diazo compound. 

The advantages in using the Ionamines would appear to be their 
solubility in water, and the fact that they are not precipitated by 
acids, alkalies, or salt, and under suitable conditions can be applied 
in the same dye bath with the cotton colors. One of the main diffi- 
culties which may arise in their practical application is the matter 
of obtaining a wide range of dyes that will hydrolyze, within 
reasonable limits, at approximately the same rate under similar 
conditions in the dye bath, as regards acidity or alkalinity and 
temperature. This may become a matter of considerable impor- 
tance in large scule dyeing of the various innumerable mixtures 
required for all shades. 

It is also stated that under certain conditions of applying the 
developed Ionamines the silk may lose its luster or go “blind,” 
possibly due to the formation of crystalline compounds on or near 
the surface of the fiber. In fact it is claimed that such a crystal- 
line formation can be seen with the microscope under certain con- 
ditions. Such blindness may also occur with other developed 
colors on acetate silk and is not confined to the Ionamines alone. 
In general the Ionamines have a greater affinity for Celanese than 
for Lustron, and therefore, when applied in the same bath, the 
Celanese is usually somewhat darker than the Lustron. However, 
the Ionamines as well as the other developed colors may be used 


270 ACETATE SILK 


on Lustron and Rhodiaseta just as well as on Celanese with the 
same fastness properties. As the actual coloring matter is usually 
largely produced within the fiber, the dye bath is generally clear 
throughout the dyeing operation, the color penetrating well and 
remaining firmly fixed in the fiber. 

Method No. 71: Dyeing Acetate Silk with Ionamine A. lona- 
mine A is used mainly for black with B-hydroxynaphthoic acid 
but may also be used as a direct yellow (2 per cent). Its various 


fastness properties are given in Table XLIX. This dye is not as . 


soluble as most of the Ionamines but the presence of a certain 
amount of insoluble dye does not interfere with either its level- 
ing or penetrating properties, and it exhausts well from the dye 
bath. Five per cent of the Ionamine with six per cent of B-hydro- 
xynaphthoic acid gives a good black which is the standard for 
acetate silk. The acetate silk scoured by Method No. 10, without 
the souring, is entered into the lukewarm dye bath containing the 
dye and 2 per cent of soda ash or 1 per cent of formic acid. In 
one-half hour the temperature of the bath is raised to 75° C. 
(170° F.) and held there for three-quarters to one hour when the 
bath should be exhausted. In place of the formic acid, 2 per 
cent of soda ash, 0.25 per cent of sulfuric or 0.5 per cent of hydro- 


chloric acid may be used in the dye bath, but salt or sodium sul-, 
fate are of no advantage. If the shade is not to be developed, the 


goods may pass through an alkaline bath containing a little am- 
monia or soda ash. ! 

Method No. 71-A: Diazotizing the Ionamines. If the shade is 
to be diazotized, it is rinsed without neutralizing the acid and 
diazotized in a bath containing 5 per cent of sodium nitrite and 10 
to 15 per cent of 32° Tw. hydrochloric acid for 20 minutes for 
medium shades. : 

Method No. 71-B: Developing the Ionamies. The diazotized 
acetate silk is rinsed and entered into a cold developing bath con- 
taining 3 to 6 per cent of developer, on the weight of the goods, 
and the temperature raised to 50 or 60° C. (122 or 140° F.) for 
about one-half hour. Under-development may occur at lower 
temperatures. When B-hydroxynaphthoic acid is used as the devel- 
oper, as for black, it should be dissolved by boiling it with one-half 


THE IONAMINES a271 


of its weight of sodium carbonate in water, or treating it with 
sodium hydroxide solution. The B-hydroxynaphthoic acid devel- 
oping bath should contain about 300 parts of water to each part of 
developer, and before entering the diazotized goods, the bath 
should be made slightly acid by the addition of about an equal 
weight of glacial acetic acid, or its equivalent. The condition of 
the developed acetate silk may be improved by rinsing well and 
soaping for 20 minutes at 50° C. (122° F.) in a bath containing 
* pounds of soap per 100 gallons of water. When B-naphthol is 
used as the developer, the bath should be slightly alkaline, and 
is prepared by dissolving the naphthol in a minimum amount of 
sodium hydroxide solution, which is usually about an equal weight 
of 76° Tw. solution. This is diluted in the developing bath and 
used cold. 

Tonamine B may be applied in the same manner as Ionamine A, 
Method No. 71, except that 2 per cent of formic acid should be 
used. When dyed direct, 5 per cent gives a deep orange color. 
When this is diazotized and developed with 6 per cent of B-napthol, 
as in Method No. 71-A, a bright scarlet is obtained. Substituting 
the same quantity of resorcinol or B-hydroxynaphthoic acid for the 
B-naphthol gives cerese or crimson-red, respectively. 

Method No. 72: Ionamine H. Ionamine H is used both as a di- 
rect shade for a yellowish green (2 per cent) or with B-naphthol 
for bluish-red. It may also be developed with resorcinol or B-hy- 
droxynaphthoic acid. In the latter case a bluish-violet is obtained 
which is sensitive to both alkalies and acids. It has good penetra- 
tion. - The dye is soluble in hot water and is applied in the same 
manner as in Method No. 71 for Ionamine A, except that 2 per 
cent of formic acid is used, or 1 per cent of sodium carbonate may 
be substituted for the acid. One-half per cent of sulfuric or 1 per 
cent of hydrochloric acid may also be used in place of the formic 
acid. It is diazotized and developed in the same manner as in 
Methods No. 71-A and No. 71-B. 

Method No. 73: Ionamine L paste. This Ionamine is in the 
form of a paste and is very soluble in water. It has good pene- 
trating properties and may be used alone as a direct yellow, or 
with the various developers as shown in Table XLIX. It is ap- 
plied as in Method No. 71 but with only 1 per cent of formic acid, 


a2 ACETATE SICK 


and may be finished or developed as in Method No. 71-A and 
No. 71-B. B-Naphthol developer is prepared as in Method No. 
Y1-B or resorcinol is dissolved in hot water only and used in a 
bath containing 6 per cent of developer. In any of these develop- 
ing baths, if a standing bath is used, an addition of about 2 per 
cent of developer is made after each lot of goods has passed 
through the bath. | 

Ionamine MA gives a direct yellow on acetate silk which may 
be developed to orange or red shades with B-hydroxynaphthoic 


TABLE XLIX 
FASTNESS PROPERTIES OF THE IONAMINES 


Ionamine A 


B-hydroxy- 
naphthoic 
Direct Acad B-naphthol Resorcinol 
ee 
Shade Yellow nets or Navy  Reddish-purple Reddish-brown 
lue 
Washing very good very good 
Mineral 
Acids Poor very good 

Soda very good good 


Perspiration very good very good 
Hot Pressing very good very good 


Light poor fairly good 
Ionamine H 
Direct B-Naphthol B-hydroneaae Resorcinol 

ct 
Orange-Yellow Reddish-Purple Purple Reddish-Brown 
very good very good 
poor good very poor 
fair fair very poor 
very good very good 
good good 
good poor 

Ionamine L 
Direct Resorcinol B-Naphthol  B-hydroxynaphthoic Acid 

Dull Yellow Reddish-Brown Purple Bright Blue 
very good very good very good very good 
poor good very good very good 
poor poor very good fair 
very good very good very good very good 
very good very good very good very good 
fairly good good poor poor 


Ionamine B 
Direct (5%) Resorcinol B-Naphthol B-hydroxynaphthoic Acid 
Deep Orange Reddish-orange Scarlet Crimson 


Inn 


THE IONAMINES 273 


acid. JIonamine Red GA gives a terra-cotta red (1 per cent) 
which may be developed. Ionamine Red KA gives a direct scarlet 
which may be developed with resorcinol to orange brown; B- 
naphthol to a claret; or with B-hydroxynaphthoic acid, to a bor- 
deaux shade. JIonamine Orange CB gives very brilliant direct 
shades of excellent fastness. The above are generally applied 
from a dye bath containing 2 per cent of formic acid at about 75 
to 80° C. (167 to 176° F.). TIonamine Blue B is the latest addition 
to the list. It is very fast to light and washing, being equal to 
the Duranol dyes in this respect. It is a readily soluble powder 
and should be applied without mineral acids. Table L gives some 
properties of the direct Ionamines. 

All of the Ionamines may be dyed with 1 to 2 per cent of formic 
acid, and Ionamines MA, B, and H, with sodium carbonate, as in 
Method No. 71. The Ionamines are used as follows :4 

For direct dyeing only 


Ionamine Red KA 
Ionamine Orange CB 
Ionamine Blue B 
For both direct and developed dyeings 


Ionamine MA (yellow) 
Ionamine B (orange) 
Ionamine GA (red) 


For diazotized and developed dyeings only 


Ionamine H 
Ionamine L paste 
Ionamine A 


TABLE L 
PROPERTIES OF THE DIRECT IONAMINES 
Name Type Properties 
Ionamine Primary Gives a slightly phototropic golden yellow color 
Yellow MA which closely resembles that of Ionamine B 
in all its fastness properties. 
Ionamine Primary The original Ionamine B 
Orange B 
Ionamine Secondary Gives a bright reddish-orange very fast to light, 
Orange CB penetrates twist better than B, and is suitable 
for all classes of work. 
Ionamine Primary Gives a terra-cotta red color, exhausts well, and is 
Red GA anf fast to light. Suitable for all classes of 
work. 


Ionamine Red Secondary Dyesa red and gives a solid shade on unions with 

Chlorazol Fast Red K, of good fastneéss to light. 
Ionamine Gives a sky blue color very fast to light and 
Blue B washing. 


a4 ACETATE SILK 


When the Ionamines are used with the direct cotton dyes on 
acetate silk-cotton unions, it is best to apply them from an alkaline 
or soda ash bath rather than from an acid bath, and most of the 
Ionamines may be applied in this manner. The following abstracts 
give some information as to the general methods of manufacture, 
the products used in, and the constitution of the Ionamines. 


The Ionamines Patents 


What appears to be the first patent covering the Ionamines is 
British Patent No. 197,809, April 5, 1922, to A. G. Green, at = & 
Saunders, and the British Dyestuffs Corporation, and covers a 
process of manufacture. United States Patent No. 1,483,798, Feb- 
ruary 12, 1924, covers the same process. In this patent it states 
that although compounds having the general formula X.N2. Y.NH. 
CH..SOsH are very unstable in alkaline solution, those containing 
a nitro group in the para-position of the nucleus (X), may be 
reduced with sodium sulfide to the corresponding diaminoazo com- 
pounds, without splitting off the methyl-omega-sulfonic acid 
radicles. 

In the same manner disazo compounds having the general 
formula X.No.Y.Ne.Z.NH.CH2.SO3H, in which X contains a 
para-nitro group, may be reduced to the corresponding diamino- 
disazo compounds. By subsequent treatment of these diaminoazo 
compounds with sodium bisulfite formaldehyde, a second methyl- 
omega-sulfonic radicle may be introduced. For example: When 
13.8 parts of p-nitroaniline are diazotized and coupled with 20.9 
parts of sodium methylaniline-omega-sulfonate, on neutralizing the 
resulting 1300 parts of solution with sodium carbonate and stir- 
ring, most of the nitroazo dyestuff will separate as a fine sus- 
pension. On adding a cold solution containing 50 parts of sodium 
sulfide crystals in 200 parts of water, and stirring for 16 hours, 
complete reduction is effected, and the resulting diaminoazo com- 
pound may be salted out, filtered off and used to dye acetate silk 
from a slightly acid dye bath. It has no affinity for cotton. In the 
same manner 13.8 parts of diazotized p-nitroaniline may be 
coupled with 25.9 parts of sodium methyl-a-naphthylamine-omega- 
sulfonate (CioH7.NH.CH2.SO3Na). The product is reduced with 


THE IONAMINES a5 


60 parts of sodium sulfide crystals to give a water-soluble product 
which dyes acetate silk directly from a slightly acid bath. 

British Patent No. 200,873 (1922) and United States Patent 
No. 1,483,797, February 12, 1924, to Green, Saunders, and British 
Dyestuffs Corporation, cover the application of the Ionamines. It 
specifies methyl-omega-sulfonic acids, derived from amino- or 
monoalkylamino-azo compounds, dissociated slowly in hot aqueous 
solutions which are slightly acid or alkaline, and the free (colored) 
amino- or alkylamino-azo bases thereby liberated are readily ab- 
sorbed from solutions by the acetate silk. The colored bases ab- 
sorbed by the acetate silk may be diazotized and developed with 
suitable phenols, amines, or aminophenols, with consequent change 
of shade. In this manner acetate silk may be dyed many shades 
except green. Ethyl-omega- “sulfonic acid and analogous acids are 
also mentioned, but they are less stable towards acids and alkalies. 
In printing the alkyl-omega-sulfonic acid is applied in a thickened 
paste containing an organic acid, after which it is dried and 
steamed. 

British Patent No. 212,029, January 13, 1923, and United States 
Patent No. 1,483,798, February 12, 1924, to Green, Saunders, and 
British Dyes, cover the production of acetate silk azo dyes con- 
taining dialkyl- -omega-sulfonic groups such as sodium ethylmethyl- 
aniline-omega-sulfonate, coupled with diazo compounds from p- 
and m-nitroaniline and dinitroaniline to obtain dyes giving red- 
orange, yellow, and bluish-red shades, respectively. These may 
also be used as acid dyes on animal fibers. 

For example: 13.8 parts of m-nitroaniline are diazotized and the 
solution added to a cold concentrated aqueous solution of 23.7 
parts of sodium ethylmethylaniline-omega-sulfonate. Sodium car- 
bonate is added to faint alkalinity, when the dyestuff separates out. 
This dye readily hydrolyses in the dye bath and gives a golden 
yellow shade on acetate silk from either acid, neutral, or alkaline 
dye baths. 

In British Patent No. 212,030, January 15, 1923, to Green, 
Saunders, and G. H. Frank, it is suggested to couple diazotized p- 
aminobenzeneazoanilinemethyl-omega-sulfonic acid, and other di- 
aminoazomethyl-omega-sulfonic acids with m-phenylenediamine, 


276 ACETATE SILER 


the former giving a red shade on acetate silk; or diazotized p- 
aminobenzeneazo-B-naphthylaminemethyl-omega-sulfonic acid with — 
aminonaphtholdisulfonic acid (H-acid). Such dyes prepared from 
these or similar components, if without any sulfonic group at- 
tached to the benzene or naphthalene nucleus, may be used to dye 
acetate silk; while the similar dyes containing such sulfonic groups 
dye animal fibers. Many azo dyestuffs of the general formula 
P.N :N.X.N :N.Y.NH.CH2.SO3H and P.N:N.X.N:N.Y.N:N.Z. 
H.CH».SO3H, where P is a phenol, carboxyphenol, aminophenol, 
naphthol, aminonaphthol, dihydroxynaphthalene, or m-diamine, or 
a sulfonic acid thereof, may be prepared by diazotizing diamino- 
azomethyl-omega-sulfonic acids, and coupling the diazo compound 
so obtained with the above derivatives, the methyl-omega-sulfonate 
being unaffected. 

For example: 37.8 parts of the sodium salt of the dyestuff ob- 
tained by combining p-nitrophenyldiazonium chloride with methyl- 
B-naphthylamine-omega-sulfonic acid and reducing with sodium 
sulfide, are diazotized in 2400 parts of water, and the product 
added to an alkaline solution of 42 parts of 81 per cent amino- | 
naphthol and disulfonic acid H. After 12 hours stirring the solu- 
tion is neutralized, heated to 45° C. (113° F.), and the dye salted 
out. This product dyes wool a blue shade from an acid bath. 

According to British Patent No. 238,717, September 17, 1924, 
to W. H. Perkin, A. W. Fyfe, and the British Dyestuffs Corpora- 
tion, the soluble N-methyl-omega-sulfonic acid of diaminochrysa- 
zin is prepared by treating the free base with formaldehyde bisul- 
fite in the absence of a strong mineral acid. The dye may be 
crystallized or salted out and is washed and dried. 

British Patent No. 252,922, July 8, 1925, to the British Dye- 
stuffs Corporation, W. H. Perkin, A. W. Fyfe, and M. Mendoza, 
states that better yields of N-methyl-omega-sulfonic acid deriva- 
tives of 1,4- and 1, 8-diaminoanthraquinone are obtained in the 
absence of strong mineral acids, by the process described for di- 
aminochrysazin in British Patent No. 238,717, than by the process 
of British Patent No. 23,968 of 1899, although in the case of 
1, 5-diaminoanthraquinone good results are only obtained in the 
presence of strong mineral acid. When the base is prepared in a 


THE IONAMINES Qav% 


finely divided condition by solution in sulfuric acid and dilution 
with water, and then washed free of acid with water, very little 
more than the theoretical amount of formaldehyde-bisulfite is 
required. Thus, one gram molecule of 1, 4-diaminoanthraquinone 
is dissolved in 1600 grams of sulfuric acid and after 2 hours 
agitation at 100° C. is cooled and diluted with 20 liters of ice cold 
water. After decanting off the acid waste water and washing 
the precipitate on the filter, first with water and then with 2 per 
cent of soda to slight alkalinity, the paste is incorporated with a 
mixture of 2.5 molecules of 40 per cent sodium bisulfite and 2.5 
molecules of 40 per cent formaldehyde. The mass is diluted with 
500 cubic centimeters of water and stirred under a reflux for 8 
hours at 100° C., when a liter of saturated salt solution is stirred 
in and the omega-sulfonate filtered off after cooling. In the case 
of the 1, 8-diaminoanthraquinone conversion is complete in about 
12 hours. 

United States Patent No. 1,609,702, December 7, 1926, to W. 
Duisberg, W. Hentrich, and L. Zeh, covers the use of amino- 
anthraquinone-N-methyl-omega-sulfonic acid compounds for dye- 
ing acetate silk, ethylcellulose, and related compounds. 


References 


1A. G. Green and K. H. Saunders, J. Soc. Dyers and Colourists 39, 10-16 
(1923), and 4o, 138-41 (1924). 

* Bucherer and others, Ber. 39, 2796 and 2814. 

°F. M. Rowe, J. Soc. Dyers and Colourists 42, 207-8 1926). 

* British Dyestuffs Corporation, “Dyeing and Printing of Artificial Silks,” 
(1926). 


GHAPTER Naa 


THE DISPERSOL TYPE OF DYES, OR DYEING BY 
COLLOIDAL SOLUBILIZATION OF THE DYES 
THE 2. RA yee 


Tue dispersol type of dyestuffs or method of application, which- 
ever we may care to call it, is the second entirely new group of 
dyestuffs to be developed especially for use upon acetate silk. Their 
announcement and appearance upon the market closely followed 
that of the Ionamines, the first products for this particular pur- 
pose. They are the result of considerable research and experience 
in England by the British Dyestuffs Corporation, the British 
Celanese Company, and others, in their search for dyestuffs adap- 
table to, or special methods of application particularly suited for, 
acetate silk. They are entirely the result of English research; 
and these two new products, the Ionamines and dispersol dyes, 
the latter group including the S.R.A., Celatene, Duranol, and 
Dispersol dyes, very clearly bring out the high type of research 
which appears to have become rather common in England since 
the war. 

In the previous chapters the affinity of acetate silk for a large 
number of dyes, bases, etc., containing certain specific chemical 
groups or characteristics, has been repeatedly pointed out. Many, 
in fact, most of these compounds are not soluble in water, and 
the wide variety of methods which have been attempted in order 
to overcome this insolubility have been pointed out. The dis- 
persol dyes are merely another attempt to overcome this in- 
solubility of compounds having an affinity for acetate silk, but the 
modus operandi is entirely new, in that they are solubilized by 
physical methods and not by chemical methods, as in the usual 
procedure. 

It is a heretofore unexpected fact, possibly not at all character- 
istic of dyeing acetate silk only, that certain compounds (dye- 
stuffs) have a much greater affinity for acetate silk when in col- 


278 


Pere nowlL TYPE OF DYES 279 


loidal solution, possibly in even a rather coarse dispersion, than 
when they are in true solution. This is particularly the case where 
the compound is solubilized by means of chemical combination 
with some solubilizing reagent, such as the solubilization of certain 
bases by means of hydrochloric acid to form their hydrochlorides, 
or by sulfonation. 

When the dyestuff is solubilized by the chemical method, as 
the sulfonate or hydrochloride, it is a case of the fiber’s chemical 
and physical affinity for the basic portion of the dyestuff against 
that of the acid radicle and the water. Where the physical method 
of solubilization is used, such as in the dispersol process, there is 
no acid radicle affinity present in the dye bath, and the solubility of 
the dyestuff in water is usually so low that the compound is on the 
point of actual precipitation. As the attraction in this case is 
practicaly all one way, that is towards the fiber (acetate silk), it 
is not surprising that deeper shades are obtained than by the older 
chemical methods of solubilization, where at best, the dyestuff 
only comes to equilibrium between the aqueous-acid phase and 
the nonaqueous fiber phase. 

Where the chemically solubilized dyestuff is highly hydrolyzed 
in the dye bath, as in the case of the Ionamines, we may expect 
the free basic portion of the hydrolyzed molecule to enter into 
either physical or, in this case, more probably chemical combina- 
tion with the nonaqueous (fiber) phase, in which it appears to 
be more soluble than in water, and which is acidic in character, 
due to the acetate groups present. This in turn allows a further 
hydrolysis of the dyestuff, with a further absorption of free base, 
etc. Here there is probably an equilibrium reached between the 
aqueous-acid phase and nonaqueous-acid (fiber) phase, while with 
the physically solubilized dyestuff, there is more likely to be prac- 
tically a complete exhaustion of the colloidal dyestuff up to the 
point of saturation of both the chemical and physical affinities of 
the fiber. . 

If we neutralize an aqueous base-hydrochloride solution with 
an alkali, such as sodium carbonate, the free base is precipitated 
as a colloidal or even coarser dispersion in the bath and this free 


280 ACETATE SILK 


base is rapidly taken up by the acetate silk, as was mentioned in 
connection with the application of bases for the developed colors 
on acetate silk,2 and we get much deeper shades than where we 
depend only upon the hydrolysis of the dyestuff (base-hydro- 
chloride) to dye the fiber. 

A particular case of this kind, in which the dispersion dyes 
acetate silk, while the solution does not, is shown by Spirit Red 
III (o-tolueneazo-o-tolueneazo-B-naphthol). When this dyestuff 
is dissolved in alcohol, the solution does not dye acetate silk, but 
upon pouring the alcoholic dyestuff solution into water, whereby 
the dyestuff is precipitated as a fine dispersion, it dyes acetate 
silk. For examples of.the base-hydrochloride phenomenon, we 
have only to refer to the application of the bases to acetate silk 
for developed or azo colors. In the case of sulfonated dyes, the 
hydrolysis of the sulfonated color acid is probably so slight that 
the acetate silk is dyed very light shades in only a few cases. 

Somewhat along the same line is the fact that acetate silk may 
be dyed a pure yellow shade by means of tartrazine from a bath 
containing (a) 0.75 per cent of sodium dioxytartrate dissolved 
with just sufficient hydrochloric acid, and (b) 1.3 per cent of phe- 
nylhydrazine dissolved in acetic acid. The two solutions (a and 
b) are mixed in the dye bath and the acetate silk immediately 
entered. It is turned for 10 minutes cold, the temperature gradu- 
ally raised to 50° C. (122° F.), and the dyeing continued for 20 
minutes. Any cotton present is not stained and the color on the 
acetate silk is fast to soaping at 40 to 50° C. (104 to 122° F.). 
By substituting p-nitrophenylhydrazine for the phenylhydrazine 
in b, an orange shade results. A terra-cotta color is obtained in 
a similar manner, in a single bath containing “‘nitrosamine” and 
1, 2, 4-toluylenediamine in the presence of acetic acid. 

In the same manner, many other comparatively insoluble color- 
ing matters, such as Induline, Nigrosine, Rosaniline Base, Methyl 
Violet Base, as well as other compounds, not necessarily all bases, 
when in a more or less highly dispersed or colloidal condition, 
have a high affinity for acetate silk. The dispersol dyes offer a 
very easy and convenient method of obtaining these insoluble 


* See Chapter XVI. 


Pree hol TYPE'OFR DYES 281 


products in a dispersol or colloidal condition on a commercial 
scale, and undoubtedly many of the products previously men- 
tioned as suitable dyestuffs, may be, or are, applied by this method. 

In discussing the development of the S.R.A. dyes, Dr. Ellis,! 
who was a pioneer of this particular work, says that the experi- 
mental research upon the application of the various older and 
specially prepared dyestuffs to acetate silk developed a few rules 
very similar to those which led to the development of the Iona- 
mines: (a) That the substantive affinity of a dyestuff for acetate 
silk is roughly proportional to the basicity of the dyestuff, and 
likewise approximately inversely proportional to its acidity or to 
its powers of salt formation with bases. This explains the com- 
paratively high affinity of the basic dyes, many azo compounds, and 
the simple azo bases, as against the feeble or total lack of affinity 
by the acid and salt or cotton dyestuffs. Clavel’ attempted to 
classify the various chemical groups usually found in dyestuffs 
in regard to their numerical preponderance over one another in 
dyeing acetate silk, however, among other things he failed to in- 
clude in his generalizations the matter of the orientation of the 
groups in the dyestuff molecule, which is a very important factor. 

(b) That the substantive affinity of a dyestuff for acetate silk is 
proportional to its molecular simplicity or inversely proportional 
to its molecular complexity or aggregation. Ellis states that 
whether chemical or physical solution theories be correct for the 
dyeing of acetate silk, this second generalization probably re- 
solves itself into the question of simple “accessibility” of the dye- 
stuff to the material of the filament, that is, the diffusion or non- 
diffusion through, the semipermeable membrane of the filament 
surface. Apparently the size of the dyestuff molecule to some 
extent regulates the speed of diffusion of the dyestuff into the 
interior of the acetate silk.° 

These rules, after much research and practical experience, led 
to the development of this new class of dyestuffs and method of 
dyeing acetate silk. It is a question just how many of the products 
used in this manner are really new compounds, but it is certain 


» British Patent No. 182,830. 
* See Chapter VIII. 


282 ACETATE SILK 


that the method of application is new. In other words, it is pos- 
sible that some or perhaps many of the dyes used are more or 
less well-known compounds, which are comparatively insoluble 
in water and other common solvents, but the physical method of 
solubilizing them for application to acetate silk is new. While 
the dispersol dyes were developed particularly for use on acetate 
silk, at least some of them are applicable to other fibers, as men- 
tioned in some of the patents following. In fact many of these 
commercial products stain or dye wool and true silk more than 
may be desired where contrasting two color effects are wanted. 

In developing the S.R.A. dyes, it was found that many com- 
paratively water-insoluble commercial dyestuffs, bases, etc., as 
well as some new insoluble dyes were soluble in highly sulfonated 
castor oil or concentrated SulfoRicinoleic Acid (from which the 
S.R.A. dyes receive their name), some of them apparently form- 
ing salts with the sulforicinoleic acid, which were soluble in ex- 
cess of the solvent (acid), as in the case of S.R.A. Orange I. 
Most of them are also soluble in many other oleaginous com- 
pounds of salt-forming characteristics, such as the higher fatty 
acids and their salts, etc., as well as in many other organic com- 
pounds ; and apparently in the case of the Duranols, Celatenes, and 
Direct Azonines, some such other solvent compound is used in 
place of the sulforicinoleic acid mentioned. Some of the recent 
patents along this line, as given in Chapter XXIII, may be of in- 
terest in this connection. 

When once they are in solution, the solvent solution of the dye- 
stuff may be placed directly in the dye bath without precipitating 
out the insoluble dyestuff. The dyestuff appears to remain in col- 
loidal solution and the bath may be neutralized or even frequently 
made slightly alkaline to advantage. Under such conditions the 
dyestuffs pass through the ordinary dye-house cloth filter, or even 
through filter paper, and are readily taken up by the acetate silk. 

In this manner it was found possible to dissolve and apply such 
insoluble products as the following to acetate silk: Nitrobenzene- 
azobenzeneazo-2-naphthol (Sudan I11); Benzeneazodimethylani- 
line (Oil Yellow D); m-Nitrobenzeneazodiphenylamine; Nitro- 
benzeneazo-2-naphthol (Para-Red); 4-Nitro-2-methoxybenzene- 
1-azodiphenylamine ; p-Acetamidobenzeneazo-1-naphthylamine; p- 


Pere nok LYPE-OrR DYES 283 


Aminobenzeneazonaphthaleneazodimethylaniline ; Aminoazonaph- 
thalene; p-Aminobenzeneazophenylmethylpyrazolone; Dimethyl- 
p-aminophenyl-1, 4-naphthoquinonimine (Indophenol Blue); 1- 
Aminoanthraquinone (Yellow); %-Aminoanthraquinone; 1-p- 
Tolylamino-4-hydroxyanthraquinone; Rosaniline base; Safran- 
nine base; Methylene Blue base; p-nitroaniline; Benzidine; Dia- 
nisidine; Aminoazotoluene; and Di-p-methoxybenzoyldiamino- 
anthrarufin, as well as a host of other more or less similar 
products. 

At the present time there is available a wide range of S.R.A., 
as well as other brands of dispersol dyes, which give direct shades 
on acetate silk ranging from lemon-yellow to dark blue or even 
black. There was also originally a group of products for diazo- 
tization and development on the fiber known as the Diazo Sola- 
mines.” These Solamines were later withdrawn and at present 
the only S.R.A. colors which it is usually necessary to diazotize 
and develop are S.R.A. Blacks III and IV. It is claimed that 
the dyeing of acetate silk by means of dispersol dyes is no more 
expensive and in some cases is cheaper, than the dyeing of cotton 
or the older rayons with colors of equal fastness. 

In perfecting the series of dispersol dyes, the property of 
phototropism* again came into prominence, as in the development 
of the Ionamines, but the difficulty was again overcome satisfac- 
torily. As before, the trouble was particularly prevalent on the 
greenish-yellows. While the exact constitution of the various 
S.R.A. dyes has not been divulged, probably at least one each 
of the S.R.A. and Celatene Yellows are nitroamino derivatives, 
and a review of the patent literature indicates that some of the 
others are simple azo and aminoazo compounds, possibly the yel- 
lows, oranges, and reds; while perhaps most of the violets and 
blues are of the anthraquinone series. Some of these are soluble 
in cold Turkey-red oil, etc., while others require heating. The 
S.R.A. dyes have been used in England since 1923. 

The S.R.A. dyestuffs and their methods of application are 
controlled by the British Celanese Company and its branch, the 
American Cellulose and Chemical Company, and may only be used 


“See Chapter VIII. 


284 ACETATE SIEK 


in conjunction with their product, Celanese. It is understood 
that they are now manufactured in America by the American 
Aniline Products Company. However, the Celatene and Duranoi 
dyes® appear to give very similar results on Lustron, Rhodiaseta 
and Celanese. In fact it has been stated that nearly all substances 
capable of dyeing acetate silk may be applied to some extent by 
means of a dispersing agent. However, dyes having no direct 
affinity for this fiber, such as most direct and certain sulfonated 
acid dyes, cannot be applied by this method. 

For certain purposes the use of a highly sulfonated castor oil 
in preparing the dispersol pastes is an advantage over the use of 
Turkey-red oil. When Turkey-red oil is used, only alkaline or 
neutral dye baths may be employed, but with the more highly sul- 
fonated product, an acid bath may be employed and in dyeing 
acetate silk-wool unions in a combination dye bath this is cer- 
tainly an advantage. Certain organic solvents, such as glycerol, 
epichlorohydrin, ethylene chlorohydrin, naphthalene-formalde- 
hyde condensation products, etc., have been suggested as dispersing 
agents. Some of the solvents discussed under Solvent Dyeing in 
Chapter X VIII may also be applicable, as well as some of the new 
hydrogenated solvents, such as Tetraline, Hexalin, or Decalin. 
Some of these are now made in America by the Newport Chemi- 
cal Works. 

It is interesting to note that most dyes upon acetate silk con- 
form more closely to simple rules governing the relationship of 
their chemical structure to their resistance to acids, alkalies, wash- 
ing, and light, than is the case with any other fiber. Most of the 
dispersol dyes on the market have excellent fastness to the above 
as well as to soaping, ironing, volatility, perspiration, rubbing, 
phototropism, cross-dyeing of cotton or wool, domestic usage, 
weathering, etc. Table LI gives the colors obtained with the vari- 
ous S.R.A. dyes. It has been stated that all of the S.R.A. dyes 
are individual chemical compounds and that none of the follow- 
ing dyes are blends of two or more other dyes. 

Table LII gives information regarding the fastness of the 
S.R.A. dyes on Celanese. The light fastness tests were made 


*See Chapter No. XXII. 


Pew TYPE OF DYES 285 
TABLE LI 
COLOR OF THE S.R.A. DyEs ON CELANESE 
S.R.A. Pure Yellow I Lemon 
S.R.A. Pure Yellow II Greenish-Lemon 
S.R.A. Golden Yellow VIII Daffodil 
S.R.A. Golden Yellow IX Old Gold 
fS.R.A. Fast Golden Yellow X Golden Yellow 
fS.R.A. Fast Golden Orange I Marigold 
fS.R.A. Fast Golden Orange III Golden Orange 
S.R.A. Orange I Tangarine 
S.R.A. Orange II Brilliant Orange 
S.R.A. Orange III Brilliant Orange 
SRA. Pink II Pink 
S.R.A. Red I Scarlet Red 
S.R.A. Red III Crimson Red 
S.R.A. Red V Violet Red 
fS.R.A. Fast Red VII Red 
fS.R.A. Fast Heliotrope I Bright Heliotrope 
fS.R.A. Fast Violet II Brilliant Bluish-Violet 
fS.R.A. Fast Blue III Reddish-Blue 
fS.R.A. Fast Blue IV Pure Blue 
S.R.A. Blue V Deep Blue 
S.R.A. Fast Black III (B-hydroxy- 
naphthoic acid) Full Greenish-Black 
S.R.A. Fast Black IV (B-hydroxy- 


naphthoic acid) 


Full Bluish-Black 


In the above list the dyes marked f are particularly fast to light and com- 
pare in this respect with the vat dyes on cotton. 


TABLE LII 
FASTNESS PROPERTIES OF THE S.R.A. DYES ON CELANESE 


Dye Light Soaping Organic Acids Alkalies 

S.R.A. Pure Yellow I g. g. e e. 
S.R.A. Pure Yellow II g. e. e e. 
S.R.A. Golden Yellow VIII V.g. V.g. e e. 
S.R.A. Golden Yellow IX V.g. v.g. V.g. e. 
S.R.A. Golden Orange I e. V.g. e f.g. 
S.R.A. Orange I v.g. e. e e. 
S.R.A. Orange II g. Vic; e e 
S.R.A. Pink II (recommended for 

underwear only) f. g. g. — 
S.R.A. Red I g. e. e. e 
S.R.A. Red III g. e. e. e 
S.R.A. Red V g. e. e. e 
S.R.A. Heliotrope I e. v.g. e. e 
S.R.A. Violet II v.g. v.g. e. e 
S.R.A. Blue III e. v.g. e. e 
S.R.A. Blue IV v.g. v.g. e. e 
S.R.A. Blue V g. v.g. e. e 
S.R.A. Black IV (B-hydroxy- 

naphthoic acid) e. e. e. 1 AAS 


fre_ fair taptness; ¢ = good; v.g. = very good; ex. = excellent. 


286 ACETATE SILK 


against Indanthrene and Caledon vat dyes, and the washing tests 
against dyes such as the Chlorazol Fast, Diamine Fast, and Benzo 
Fast types. The fastness’ to light of the S.R.A. dyes bearing 
the prefix “Fast” in Table LI is such that it is hardly necessary to 
use the method covered by British Patent No. 243,841% to increase 
their fastness to light. 

The leading American authority on the S.R.A. dyes, Dort,3 
recommends the following combinations of S.R.A. dyes to obtain 


the various colors of best fastness to light: 


Violet Red 
S.R.A. Violet II S.R.A. Heliotrope I 
S.R.A. Heliotrope I S.R.A. Red III 
S.R.A. Blue IV Grays, Browns and General Mode 
Blue Shades 
S.R.A. Blue III S.R.A. Golden Yellow VIII 
ie By rene I 
.R.A. Blue or 
S.R.A. Golden Yellow Vill S.R.A. Golden Orange T 
SRA. Blue 1V S.R.A. Blue III 
S.R.A. Blue III re 
Yellow yet 
S.R.A. Golden Yellow VIII SR Ee 
Orange S.R.A. Red I 
S.R.A. Golden Orange I Black 
S.R.A. Black IV developed with B- 


hydroxynaphthoic acid. 


The best fastness to soaping is obtained with: 


®See Chapter XXII. 


Violet Red 
S.R.A. Violet II S.R.A. Red I, III, or V 
.S.R.A. Heliotrope I S.R.A. Heliotrope I 
ae poe Grays, Browns, 00) a Mode 
Blue S.R.A. Golden Yellow IX 
S.R.A. Blue IV S.R.A. Red I 
rahe S.R.A. Blue III or IV ‘ 
S.R.A. Pure Yellow II Navy 
S.R.A. Blue IV S.R.A. Blue V 
S.R.A. Golden Yellow IX S.R.A. Red I or V 
Vellan S.R.A. Golden Yellow IX 
S.R.A. Pure Yellow II Black 
S.R.A. Golden Yellow IX S.R.A. Black IV developed with 
Orange B-hydroxynaphthoic acid 
S.R.A. Orange I 
S.R.A. Golden Yellow IX 


Perey 1YPE.OF DYES 287 


While S.R.A. Orange I has a very good fastness to light, 
when used in mixtures and exposed to very bright light, it is 
phototropic to some extent. It is therefore recommended only 
for pale mode shades. For full shades of brown, etc., it is best 
Pomusemoun4. Orange IJ, Red I, or Heliotrope I. S.R.A. 
Heliotrope I in some cases has a slight fluorescent effect, which 
is not always desirable. Where only pale shades are required, 
S.R.A. Blues III and IV, Golden Orange I and Orange II, and 
Golden Yellows VIII or IX are widely used. Where medium 
shades are desired, the same blues, oranges and yellows are used, 
as well as S.R.A. Red I. For deep shades of navy blue and 
brown, S.R.A. Blue V, Golden Yellow VIII and IX, Orange 
II, and Reds I and V, are recommended. S.R.A. Orange III 
is extremely level dyeing and has good fastness to light and wash- 
ing. 

As a class most of the S.R.A. dyes show excellent fastness to 
washing and rubbing, while the fastness to acids, light and alka- 
lies varies with the particular product used, as it does when this 
same compound is applied by any other method. With the excep- 
tion of S.R.A. Blues I and II, these dyes withstand wool cross- 
dyeing very well and may be used in this manner. 

At the present time the S.R.A. dyes are marketed only as 
pastes of the dyestuffs in the solubilizing medium, of a strength 
about equal to 10 per cent pastes of the usual dyestuffs for cot- 
ton. These pastes may be placed directly in the hot aqueous soapy 
or alkaline (ammoniacal) dye bath without any further treatment. 
They are applied by the usual direct dyeing methods, preferably 
in soapy dye baths, as an aid to penetration and leveling. Many 
of them may be applied cold without sacrificing fastness. They 
do not stain cotton or other artificial silks and may be mixed in- 
discriminately together, or may be applied in the same dye bath 
with suitable direct cotton dyes, despite the apparent chemical in- 
compatability of the two groups. Sodium chloride or sulfate may 
be used in moderation to assist the cotton dye, but it does not 
benefit the dispersol dyes materially except for heavy shades, and 
it must not be present in sufficient quantity to cause salting out 


288 ACETATE SILK 


of the soap, or to cause a precipitation of dye, which may become 
superficially fixed on the fiber and cause crocking. 

Method No. 74: The S.R.A. Dyes on Celanese. The aqueous 
dye bath is usually prepared by adding about 0.5 to 1.6 grams of 
olive oil soap, or 1 or 2 cubic centimeters of Turkey-red oil or 
Celascour, per liter of dye bath, especially for pale shades and as 
an aid to penetration. In dissolving, or rather in diluting the 
dye pastes, it is best to add the fairly strong hot soap solution to 
the dye paste and then dilute this with hot water. Add this to the 
dye bath containing the balance of the soap. It is not necessary 
to heat the dye bath. Particular care must be used in dissolving 
S.R.A. Pure Yellow II, which is more difficult to bring into 
solution than the other members of the group. 

The S.R.A. dyes are frequently applied by hand, using double 
sticks. They are also dyed on a suitable machine with porcelain 
rollers. Piece goods may be dyed in the jig. Bobbins, pins, 
cheeses, and beams are not usually attempted, as yet. For skein 
dyeing, a 25 to 1 dye bath is generally used, or for piece goods a 
30 or 35 to 1 bath, but this may be varied according to the type 
of vat or machine. Copper dye vessels may be used. Materials 
of heavy or tight construction should be entered at a low tem- 
perature and worked for some time before heating the bath. It 
is also best to dye pale shades at a low temperature to insure even- 
ness. The usual practice on the general run of goods is to dye 
for a half to one hour at 40 to 80° C. (104 to 176° F.) according 
to the particular dyes used, material being handled, and result de- 
sired. As a class the S.R.A. dyes feed onto Celanese most 
rapidly at about 76° C. (170° F.). 

Most of the dye baths are clear, but a few are cloudy, even 
when heated. The most stable solutions appear to be those pre- 
pared cold and heated afterwards, instead of preparing the dye 
bath very hot. Some S.R.A. dye baths are so stable as to permit 
standing for several days without precipitation, but others will 
not. Most of these products dye level and are very fast. 

Dort* recommends a dye bath containing approximately 1.5 
grams of olive oil soap and 0.25 gram of soda ash, per liter, for 


Pie ekoOL TYPE OF DYES 289 


the application of the S.R.A. dyes. In no case should the 
amount of soda ash exceed 2 per cent, on the weight of the 
ieelanese,mine dye baths of the ordinary volume. The S.R.A. 
pastes should be dissolved in a boiling soap solution and filtered 
into the dye bath through cotton cloth. The addition of 4 to 8 
cubic centimeters of Celascour, per liter of bath, aids in penetration 
and leveling. After applying the dispersol dyes, the goods should 
be rinsed with water at 45° C. (113° F.), followed with cold 
water and then soaped. It is quite common to find some differ- 
ence in the shade of a dyed fabric before and after dyeing, but on 
Celanese this difference in shade appears to be greater than on 
most other materials. 

As the S.R.A. dyes are applied in a soapy dye bath, soft water 
is absolutely essential for their successful application. Colloidal 
solutions are inclined to be affected to a considerable extent by 
what we are sometimes inclined to consider minor factors, and for 
this reason it is always best to avoid undue complications and the 
entry of any unusual factors into the application of dyes by the 
colloidal solubilization or dispersol method. In many instances 
emulsions are affected by electrolytes, temperatures, etc., in such 
a way as to considerably influence the size of the colloidal aggre- 
gate. Such factors may have a considerable bearing upon the 
shade obtained by a given formula. 

Greenhalgh® states that hard water may also have such a dele- 
terious effect upon dispersol dyes containing anthraquinone or its 
substituted homologues as to render them valueless from a tinc- 
torial standpoint. He points out that in many cases it is not at 
all satisfactory to attempt to soften the water in the dye bath 
itself. 

Method No. 75: Topping the S.R.A. Dyes with Basic Dyes. 
The dispersol dyes may be topped with basic dyes in the same 
manner as the substantive dyes are topped on cotton. Another 
method of topping, which is particularly adapted for use in con- 
nection with the dispersol dyes, is to dissolve the free color base 
of the common basic dyes, such as Rosaniline Base, Methyl Violet 
Base, Saffranine Base, Quinoline Yellow, Indophenol, etc., in 10 


290 ACETATE SILK 


times its weight of Turkey-red oil. This solution is diluted with 
boiling 5 per cent soap solution, the whole boiled again, and may 
then be added to the dispersol dye bath and applied concurrently 
with the principal dispersol dyestuff. This of course avoids a 
separate topping operation and probably gives much better re- 
sults. 


The S.R.A. Blacks 


The S.R.A. Blacks are the only members of this group which 
tequire diazotization and development on the fiber. S.R.A. Black 
III gives a greenish-black when diazotized and developed with 
B-hydroxynaphthoic acid. Black IV is a newer dye, is extremely 
fast and gives a full bluish-black with B-hydroxynaphthoic acid. 
Since it also gives a good black with m-toluylenediamine, it is very 
suitable for use in dyeing acetate silk-cotton hosiery. It may be 
dyed in the same dye bath with a diazotizable cotton black to give 
a solid black shade upon development. 

S.R.A. Black IV is not recommended for use as a direct dye, 
but gives a variety of colors with different developers, as shown 
in Table LIII. The light fastness of these developed colors vary 
somewhat, so that they should be tested before use. In develop- 
ing the S.R.A. Blacks on Celanese, it is recommended to diazotize 
and develop the base by the usual method for other fibers and 
colors, except that the developing bath should be hot, and when 
B-hydroxynaphthoic acid is used as the developer, the developing 
bath should be distinctly acid to litmus. The addition of glue to the 
bath, while not essential, is usually advantageous. Method 76 
covers the process. : 


TABLE LIII. 

Coors OBTAINED BY DEVELOPING S.R.A. Biack IV. 
pe Developer Color 
Direct (not developed) Orange Brown 
m-Phenylenediamine Brownish-Black 
Dimethylaniline Deep Purplish-Maroon 
Resorcinol Maroon 
Naphthol AS Reddish-Blue 
B-Naphthol Deep Purple 
B-Hydroxynaphthoic Acid Bluish-Black 
m-Toluylenediamine Black 


S.R.A. Black Developer HY Special Black 


ee 0—0—°—00 


Pion. DYPE OF DYES 291 


Method No. 76: S.R.A. Black IV on Celanese. Dye at 80° C. 
(176° F.) in a 30 to 1 bath containing 15 or 20 per cent of S.R.A. 
Black IV and 1 gram per liter of olive oil soap for an hour and a 
half. The direct color will be a brownish orange. Rinse well and 
diazotize for a half hour in a 15 to 1 dye bath containing 5 per cent 
of sodium nitrite and 16 per cent of 28° Tw. (1.14 sp. gr.) hydro- 
chloric acid. Rinse again and immediately enter into a 30 to 1 
developing bath at 35° C. (95° F.) containing 2.5 per cent of 
B-hydroxynaphthoic acid, 0.6 per cent of caustic soda, 3 per cent 
of glue, and 3 per cent of 100 per cent acetic acid. During a half 
hour raise the temperature of the developing bath to 60° C. (140° 
F.) and continue the development for about a half to three-quart- 
ers of an hour at this temperature. Finish by a light soaping. 
Where a greener tone of black is desired, it may be shaded with 
S.R.A. Golden Orange I. A jet black may be obtained with 16 
per cent of S.R.A. Black IV and 4 per cent of Orange I, developed 
as above. Care must be taken to insure complete development of 
the dye or the black color will redden on washing. In applying 
black to Celanese, it is important to develop immediately after the 
diazotization, in not too dilute a bath. The addition of the acetic 
acid is an important point which must not be neglected. 


Compound Shades 


The dyeing of compound shades on any fiber is usually much 
more of a problem than the application of simple shades. As in 
the dyeing of compound shades on any other fiber, a complete 
knowledge of the characteristics and peculiarities of each indi- 
vidual component dyestuff is a prime requisite for success. Green- 
halgh® points out that this difficulty is particularly prevalent in the 
application of greens, fawns, and mole shades, with dispersol dyes, 
and says that unless very close temperature control is used in the 
dye bath, it is impossible to match shades exactly. As an instance 
of this he mentions the production of a Jade Green shade on Cela- 
nese with S.R.A. Blue IV and Golden Yellow VIII. “At certain 
stages in the dyeing operation of this shade, the result has a 
tendency to exhibit a yellowish cast, particularly if the dyeing is 


292 ACETATE SILK 


done at a temperature below that of 65° C. (149° F.), but on rais- 
ing the temperature to a higher degree this yellowness disappears, 
giving fuller tones of blue. If at this juncture an addition of 
Yellow be made to the dye bath, the bluenss is not diminished but 
on the other hand seems to be accentuated, whereas if the tempera- 
ture be lowered the preponderance of yellow is again manifested.” 

In applying the dispersol dyes to acetate silk, which in many 
ways acts just like a simple solution of the dyestuff in the fiber, 
each dyestuff apparently has a definite temperature at which it ex- 
hibits a maximum reactivity for, or solubility in, the fiber. In a 
mixture with other dyes of the same class, this may not at all 
coincide with the maximum reactivity temperature of the other 
components of the mixture. Undoubtedly these same factors hold 
good in the application of the developing or azo color bases to ace- 
tate silk from neutralized solutions of their hydrochlorides, etc. 

The following formulas for various compound shades with the 
S.R.A. dyes will give an excellent idea of what is being recom- 
mended for and used on Celanese: 


Green 
A-1: 
6.0% S.R.A. Blue IV paste and 
10.0% S.R.A. Golden Yellow VIII paste. 


A-2: Apple Green 
0.95% S.R.A. Pure Yellow II paste and 
0.12% S.R.A. Blue 1V paste. 
Enter cold and raise to 75° C. (167° F.) in an hour. 


A-3: Bright Green 3 
16.0% S.R.A. Golden Yellow VIII paste and 
%.0% S.R.A. Blue IV paste. ; 


A-4: Almond Green 
0.6% S.R.A. Blue III paste and 
2.5% S.R.A. Golden Yellow IX paste. 


A-5: Dull Green 

3.0% S.R.A. Blue II paste and 

8.0% S.R.A. Pure Yellow I paste. 

Enter cold and dye at 70 or 75° C. (158 or 167° F.) for an 
hour. 


Pieris Ol TYPE OF DYES 293 


A-6: Pale Greenish Gold 

4.0% S.R.A. Golden Orange I paste and 

0.8% S.R.A. Blue III paste. 

This may be shaded with S.R.A. Blue III and Orange I, if 
desired. 


Putty 
A-7: 

3.0% S.R.A. Blue II paste, 

0.2% S.R.A. Orange I paste, and 

1.5% S.R.A. Golden Orange VIII paste. 

Enter cold and dye at 75° C. (167° F.) for an hour. 
A-8: 

0.4 % S.R.A. Blue III paste, 

0.5 % S.R.A. Golden Yellow IX paste, and 

0.06% S.R.A. Heliotrope I paste. 

A-9: Light Tangarine 

3.5% S.R.A. Golden Orange IX paste and 

pio ou, Ked I paste. 

Enter cold and raise to 80° C. (176° F.) in three-quarters 
of an hour and dye at this temperature for three-quarters of an 
hour. 

A-10: Tangarine 

4.0% S.R.A. Orange I paste and 

0.7% S.R.A. Red I paste. 

Enter cold and dye at 60° C. (140° F.) for an hour. 
A-11: Puce 

10.0% S.R.A. Red V paste and 

1.5% S.R.A. Orange I paste. 
A-12: Pale Reddish Gold 

1.0% S.R.A. Golden Yellow IX paste and 

0.2% S.R.A. Heliotrope I paste. 

Enter cold and raise to 70° C. (158° F.) for an hour or an 
hour and a half. 

A-13: London Lavender 
0.6 % S.R.A. Heliotrope I paste and 
0.06% S.R.A. Blue III paste. 


Reds ‘ 
A-14: P.O. Red 
4.0% S.R.A. Orange I paste and 
2.0% S.R.A. Red I paste, with 
1.1% Rosaniline Base NSF 100% (See Method No, 75). 
Enter cold and raise to 75° C. (167° F.) in 2 hours. 


294 ACETATE SILK 


A-15: Brick 
0.25% S.R.A. Orange I paste and 
0.25% S.R.A. Red I paste. 


A-16: Light Strawberry 
1.5% S.R.A. Red V paste and 
0.2% S.R.A. Orange I paste. 


A-1%7: Deep Crimson 
1.2% S.R.A. Red V paste and 
6.0% S.R.A. Red III paste. 


A-18: Reddish-Violet 

5.0% S.R.A. Violet II paste and 

5.0% S.R.A. Heliotrope I paste. 

Enter cold and raise to 75° C. (167° F.) in an hour and a 
half. 


A-19: Violet 

8.0% S.R.A. Blue I paste and 

8.0% S.R.A. Red V paste. 

Enter cold and dye at 75° C. (167° F.) for an hour and a 
half. 


Fawn 


A-20: 

1.3% S.R.A. Blue III paste, 

0.5% S.R.A. Golden Orange VIII paste, and 

0.6% S.R.A. Golden Orange I paste. 
Enter cold and raise to 70° C. (158° F.) in an hour and a 
half. : 


A-21: 

0.4 % S.R.A. Blue IIT paste, 

0.65% S.R.A. Golden Yellow IX paste, and 

0.04% S.R.A. Red I paste. 

Enter cold and raise to 75° C. (167° F.) in an hour and a 
half. 


Brown 
A-22: 
8.0% S.R.A. Blue III paste, 
8.0% S.R.A. Orange I paste, and 
2.0% S.R.A. Golden Yellow VIII paste. 
Enter cold and dye at 80° C. (176° F.) for an hour and 
three-quarters. 


Peel ol 1 YPE-OR DYES 295 


A-23: 
3.0% S.R.A. Red I paste, 
10.0% S.R:.A. Blue I paste, and 
20.0% S.R.A. Golden Orange VIII paste. 
Enter cold and dye at 80° C. (176° F.) for an hour and 
three-quarters. 


A-24: Leaf Brown 
1.5 % S.R.A. Golden Orange I paste, 
ee eee bie IIT paste, and 
0.25% S.R.A. Red I paste. | 
Dye at 80° C. (176° F.) for an hour. 


A-25: Dark Beaver 

1.4% S.R.A. Blue III paste, 

4.6% S.R.A. Golden Yellow VIII paste, and 

0.3% S.R.A. Red I paste. 

Enter cold and raise to 80° C. (176° F.) in three-quarters of 
an hour and dye at this temperature for three-quarters of an 
hour. 


A-26: Golden Brown 
12.0% S.R.A. Golden Orange I paste and 
2.0% S.R.A. Blue III paste. 


A-27%: Golden Brown 

7.0% S.R.A. Orange II paste, 

2.5% S.R.A. Golden Yellow VIII paste, and 

2.0% S.R.A. Blue III paste. 

Poaereomennd dye at 75° C. (167° F.) for an hour anda 
half. 


A-28: Reseda 
3.8% S.R.A. Golden Yellow IX paste, 
1.0% S.R.A. Golden Orange I paste, and 
2.0% o.R.A. Blue IV paste. 
Enter cold and raise to 80° C. (176° F.) in an hour and a 
half. 
A-29: Nigger 
4.0% S.R.A. Golden Yellow VIII paste, 
6.0% S.R.A. Orange II or Red I paste, and 
12.0% S.R.A. Blue III paste. 
Enter cold and raise to 80° C. (176° F.) in 2 hours. 


A-30: Cordovan 
0.9% S.R.A. Red I paste, 
0.6% S.R.A. Golden Yellow IX paste, and 
0.9% S.R.A. Blue III paste. 


296 ACETATE SIEK 


A-31: Bronze 
3.0% S.R.A. Golden Yellow III paste, 
0.5% S.R.A. Red I paste, and 
2.5% S.R.A. Blue III paste. 
A-32: Flame 
0.5% S.R.A. Golden Yellow VIII paste, and 
2.0% S.R.A. Orange I paste. 
A-33: Whirlpool 
16.5% S.R.A. Blue IV paste and 
3.2% S.R.A. Pure Yellow II paste. 
Enter cold and raise to 75° C. (167° F.) in 2 hours. 
A-34: Navy Blue 
25: % S:.R Ay Blue Lit paste, 
4 % S.R.A. Golden Yellow IX paste, and 
4 % S.R.A. Orange II paste. 
Enter cold, raise to 80° C. (176° F.) in an hour and dye at 
this temperature for an hour. 
A-35: Pongee 
01 ('2vSiR-A. Orange I paste: 
0.24 % S.R.A. Golden Yellow IX paste, and 
0.244% S.R.A. Blue III paste. 


Grays 

A-36: 

2,0: %o oR. blue lipase: 

0.3 % S.R.A. Golden Orange paste, and 

0.15% .S.R.A. Orange I paste. 

Enter cold and dye at 75° C. (167° F.) for an hour. 
A-37: 

0.75% S.R.A. Pure Yellow I paste, 

3.5 % S.R.A. Blue I paste, and 

0.75% S.R.A. Orange I paste. 

Enter cold and dye at 60° C. (140° F.) for an hour. 
A-88: 

1.15% S.R.A. Blue III paste, 

0.21% S.R.A. Orange I paste, and 

0.22% S.R.A. Golden Yellow VIII paste. 

Dye at 80° C. (176° F.) for an hour. 
A-39: Medium Gray 

1:0: % SKA. Blue Lil paste; 

0.25% S.R.A. Golden Yellow IX paste, and 

0.08% S.R.A. Orange I paste. 

Enter cold and raise to 80° C. (176° F.) in three-quarters 
of an hour, and dye for three-quarters of an hour. 


PiseekhoOL TYPE OF DYES 297 


A-40: Light Gray 
0.036% S.R.A. Golden Yellow IX paste, 
0.016% S.R.A. Blue IV paste, and 
0.018% S.R.A. Heliotrope I paste. 


A-41: Dark Gray 

0.17% S.R.A. Golden Yellow IX paste, 

0.08% S.R.A. Blue IV paste, and 

Oe eo. Leliotrope [ paste. 

Prepare the dye bath with 1 gram of olive oil soap and 0.25 
Prarorecoaiiim carponate per liter. Dye at 80° C. (176° F.) 
for three-quarters of an hour. After dyeing, soap for a half- 
hour in a bath containing 2 grams of soap and 2 cubic centi- 
meters of ammonia per liter at 60° C. (140° F.). 


A-42: Champagne 
2.0 % S.R.A. Golden Yellow IX paste and 
0.015% S.R.A. Blue III paste. 


A-43: Mauve 
0.7% S.R.A. Heliotrope I paste and 
0.7% S.R.A. Violet I paste. 


A-44: Nude 
0.075% S.R.A. Golden Yellow IX paste and 
0.005% S.R.A. Red I paste. 


A-45: Sunburn 
Uae ook A. Blue IIT paste, 
0.02% S.R.A. Red I paste, and 
0.08% S.R.A. Golden Yellow IX paste. 


A-46: Silver 
0.3 % S.R.A. Blue III paste, 
0.08% S.R.A. Golden Yellow VIII paste, and 
0.03% S.R.A. Heliotrope I paste. 


References 


1G. Holland Ellis, J. Soc. Dyers and Colourists 40, 285- a (1924). 
aCe. Mullin, American Dyestuff Reporter 14, 554 (1925). 
ier. Lort, Chemicals 24, No. 19, 19-22 (1925). 

AEN ES Dort, American Dyestuff Reporter 15, 200 (1926). 

all Greenhalgh, Dyer & Calico Printer 55, 106 (1926). 

°K. Greenhalgh, Dyer & Calico Printer 55, 107 (1926). 

7G. H. Ellis, J. Soc. Dyers and Colourists 42, 184-6 (1926). 


CHARTER sad 


THE CELATENE, DURANOL, DISPERSOL, DIRECT 
AZONINE, CIBACETE, CELANTHRENE, CELLACETE, 
AND OTHER DYES FOR ACETATE SIE 


Their Properties and Application. Increasing the Light Fast- 
ness of Colors on Acetate Silk. 


From the foregoing it may be assumed that the S.R.A. dyes 
are the only members of the dispersol group. However, this is 
not the case as we have several other very important brands of 
dyestuffs coming under this classification. While it is true that 
the S.R.A. dyes were the first products belonging to this class to 
be offered commercially, the Duranol dyes of the British Dye- 
stuffs Corporation and the Celatene dyes of Scottish Dyes, Ltd., 
are very important members of this group. 

Both the Celatene and Duranol dyes are prepared dispersions of 
comparatively water-insoluble compounds in the form of pastes, 
which resemble the S.R.A. dyes to some extent. No doubt some 
of the Duranol and Celatene dyes are very similar products to cer- 
tain S.R.A. dyes. It has been stated that some members of all 
three brands (S.R.A., Duranol and Celatene) are azo compounds, 
while others are anthraquinone derivatives. Casten! states that 
the Duranol dyes are derivatives of chloro- or bromoanthraquinone 
condensed with anthranilic acid. From the literature and patents 
on the subject, as well as the properties of the products them- 
selves, the Celatene dyes also appear to consist largely of anthra- 
quinone compounds. 

Another point of wide difference between the S.R.A. dyes on 
the one hand and the Celatene and Duranol dyes on the other, is 
in the composition of the dispersing or solubilizing medium. We 
have seen how sulforicinoleic acid and soap are used in solubiliz- 
ing the S.R.A. dyes, but in the preparation of the Duranol and 
Celatene pastes, some nonsoapy medium is used. In some dyeing 
processes, as for instance where true silk or wool are present, this 


298 


Minti lANROUS DYES 299 


nonsoapy dispersing medium may offer some advantages in that 
the Celatene and Duranol dyes may be applied from dye baths 
without the addition of any other chemicals, i.e., alkalies or soap, 
and yet the shade is not affected by the presence of either alkalies, 
soap, salt, Turkey-red oil, or the other usual assistants used in the 
dye bath. These nonsoapy dispersions have an excellent stability 
in the dye bath and show no tendency to precipitate. 


The Duranol Dyes 


The Duranol dyes are the products of the British Dyestuffs 
Corporation and are marketed in America by the Dyestuffs Corp- 
oration of America, of Boston. At the present time they offer 
Duranol Orange G, Duranol Red G, Duranol Red 2B, Duranol 
Blue G, Duranol Violet 2R, and a Duranol Black. These are sold 
as 10 per cent pastes which only require dilution with water to 
the desired strength for application. They may also be printed on 
acetate silk, as discussed under printing in Chapter XXIV. Neither 
the Duranol or Dispersol dyes have any affinity for cotton but they 
all stain wool and true silk. The Duranol dyes are applied to ace- 
tate silk by Method No. 77. They have excellent fastness to wash- 
ing, alkalies, acids, perspiration, rubbing, and particularly to light ; 
good fastness to cross-dyeing and the usual fulling. 

Method No. 77: The Duranols on Acetate Silk. The dye bath 
is prepared by diluting the Duranol paste with warm water. The 
acetate silk is entered cold and the temperature slowly raised to 
75 or 80° C. (167 or 176° F.) for a half to one hour. The differ- 
ent members of the group may be mixed together in the dye bath. 
They level well and may be used in the same dye bath with most 
direct and acid dyes, in the presence of either acids, alkalies, salt, 
soap, or Turkey-red oil. While the latter two aid in leveling and 
penetrating, they also retard the exhaustion and for this reason 
should not be present to the extent of more than two or three parts, 
per part of dyestuff. Duranol Blue G does not exhaust as com- 
pletely as the other Duranol dyes and therefore for full shades 
may require a somewhat longer time at the maximum temperature.® 


300 ACETALE Sick 


Dispersol Yellow 3G Paste 


The British Dyestuffs Corporation also offer another member 
of the dispersol class of dyestuffs for acetate silk, Dispersol Yel- 
low 3G Paste. This gives a brilliant greenish-yellow shade which 
is not phototropic, when applied by Method No. 77%, as for the 
Duranols. Its fastness properties in general are similar to those 
of the Duranols, except to light, in which case it is not equal to the 
members of the other group. 


The Celatene Dyes 


The Celatene dyes of that very progressive company, Scottish 
Dyes, are one of the most successful brands of dispersol dyes on 
the market. As previously mentioned, they are largely anthra- 
quinone derivatives dispersed by means of a nonsoapy medium. 
In the discussion on the theory of acetate silk dyeing, the high 
affinity of many anthraquinone compounds for acetate silk was 
mentioned, and this may account to some extent for the fastness 
properties of the Celatene dyes on acetate silk. Probably the 
patents, which are reviewed in Chapter XXIII, give more real in- 
formation regarding their constitution than any other source. 

At the present time, the following colors are available: Celatene _ 
Yellow, Celatene Fast Light Yellow, Celatene Orange, Celatene | 
Gold Orange, Celatene Fast Light Brown, Celatene Brilliant Red, 
Celatene Red B, Celatene Scarlet, Celatene Red Violet, Celatene 
Brilliant Violet B and 2B, Celatene Blue, Celatene Brilliant Blue 
and Celatene Black. These give clear, brilliant shades of excellent 
fastness to light. 

The Celatenes will dye acetate silk under almost any condition 
which does not destroy the fiber. For instance they may be ap- 
plied either in a neutral, acid, or alkaline (soda ash) bath, with 
or without Glauber’s salt, in long or short baths, at from room 
temperature up to 75 or 80° C. (167 to 176° F.), with good re- 
sults, only the exhaustion varying somewhat under the different 
conditions, as would be expected. For certain purposes, such as 
dyeing knit goods, a short bath in a jig is used, but for yarns, 
longer baths are generally used. Method No. 78 gives a general 


Piece ANEOUS DYES 301 


idea of the process as recommended by the manufacturers. It is 
interesting to note that these products are also applicable to many 
fibers other than acetate silk. 

Method No. 78: The Celatene Dyes on Acetate Silk. The 
necessary quantity of dyestuff paste is added directly to the bath 
without any other addition and the bath warmed to about 40 to 
60° C. (104 to 140° F.). While the bath may not be clear at the 
- start, this does not in any way interfere with the results. The well 
wet-out material should be entered into this warm 20 or 40 to 1 
dye bath, according to the type of dyeing apparatus used, the 
shorter baths giving much better exhaustion. During about a half- 
hour the temperature is raised to from 70 to 85° C. (158 to 185° 
F.) while working the goods, until the desired shade is obtained. 
The exhaustion is usually fairly complete in a half to three-quarters 
of an hour. Where very dark shades are desired, it is best to 
use a standing bath and dye to shade, refreshing the bath with 
about five-eighths of the starting weight of dyestuff. The dyed 
material should be rinsed well and dried; or better yet, soaped at 
60° C. (140° F.) in a 1 per cent soap bath, to render the shade 
slightly brighter and faster to rubbing, before drying. While these 
dyes have excellent leveling properties, in case of difficulty the 
temperature of the dye bath may be lowered, for instance to 30° 
C. (87° F.) and a longer time given. It has been stated* that ace- 
isc acid will aid the exhaustion of certain of these dyes, while in 
others the exhaustion is retarded. A soluble oil, in the absence of 
acetic acid, usually brightens the shade of the dyed fiber but the 
remaining oil is usually difficult to remove from the material, 
and any oil not removed may give the fiber a rather cold feel. 

The application of these dyes depends upon their slight solubility 
in water, together with their great affinity for acetate silk. The 
small amount of dyestuff in solution when the goods enter the dye 
bath is quickly absorbed by the acetate silk, thus allowing more of 
the suspended dye to dissolve and be absorbed in its turn, until al- 
most complete exhaustion of the dye bath takes place. Two per 
cent of Celatene Red Violet will give a medium shade but as much 
as 20 or even 30 per cent (black) of some of these dyes are re- 
quired for heavy shades. Table LIV gives some information on 


302 ACE TALE Sik 


the fastness of a few of the Celatene dyes. It is interesting to 
note that Celatene Fast Light Yellow is faster to light on acetate 
silk than any of the vat yellows on cotton. 

These fastness tests were conducted as follows: Bleaching: 
The dyed yarn was bleached for an hour in a fresh 2°I'w. bleach 
bath. Hot pressing: Dyed yarn sample was pressed between 2 
pieces of mercerized cloth with a hot iron. The perspiration test 
was the same as for vat colors on cotton, using both acid and 
alkaline perspiration. Rubbing tests were made both wet and dry. 
Cross-dyeing: (a) Effect of alkaline hydrosulfite. (b) Effect of 
20 per cent sodium sulfate and 2 per cent sulfuric acid at 75° C. 
(167° F.) for an hour. (c) Effect of 1 per cent bichromate at 
"5° C. for an hour. Washing test. (a) One per cent soap at 60° 
C. (146° F.), in 3 periods of 2 hours each, or a total of 6 hours. 
(b) One per cent soap at 80° C, (176° F.). in 3 periods of 2 
hours each, or a total of 6 hours. The light test was to sunlight, 
under glass. The leveling test was made by entering a plaited 
hank of acetate silk into the dye bath at 75° C. (167° F.) and 
allowing it to remain untouched for an hour. 


TABLE LIV 
FASTNESS OF CELATENE CoLors ON ACETATE SILK 


See — 
Washing Tests 
Bleeding 
onvis- Bleeding Bleeding 
Loss coseand onwool onCel- 


Tests Light indepth cotton andsilk anese Bleaching Street Mud 
Cel. Yellow m/p. g. ex. ex. g. ex. ex. 
™ Red B. v.g. m. v.g. V.g. m. ex. ex 
” Bril. Violet B. ex. v.g. V.g. V.g. fg. ex. ex 
” Red Violet ex. g. v.g. v.g. m. ex. ex. 
” Bril. Violet 2R ex. v.g. ex. v.g. v.g. V.g. ex. 
' ” Orange v.g. /g. g. ex. g. m. ex. ex. 
” Blue g/m. V.g. V.g. V.g. ex. g. V.g. 


” Kast Light Yellow ex. 
” Kast Light Brown ex. 
06060000 


DS eeEeEeEeEeEeEeEeEeEeEeEees—seeses nnn 


Milling Cross-Dyeing Rubbing Perspiration 
Chrome 
Loss in Alkaline Glaubers and 

Tests depth Bleeding Hyrods Acid Acid Wet Dry Alkaline Acid 
aa dn ncn neon EOE SSS ee 

Cel. Yellow v.g. ex. p. ex. v.g. v.g. ex. ex. ex. 
” Red B. v.g. g. p. g. ex. ex./v.g. ex./v.g. V.2. V-&- 
” Bril. Violet B. ex. Vie.» SD: v.g. v.g. ex. ex. Vi8.0 VARS 
”» Red Violet ex. ex. p. v.g. V.g. ex. ex. Vike. 9 Vas 

” Bril, Violet2R — g. ex. p. v.g. p. ex. ex. ex. ex. 

” Orange V.g. g. p. v.g. v.g. ex./v.g. Vg. ex. ex. 

” Blue ex. Vignes ex. ex. V.g. V.g. ex. g. 


a 


p. = poor fastness; m. = medium; g. = good; v.g. = very good; ex. = excellent. 


MISCELLANEOUS DYES 303 


Hot Pressing Acid Spotting 


Change in Staining H2SO04 = Acetic Leveling 
Tests shade 

Cel. Yellow ex. ex. ex. ex. ex. 
” Red B. ex. v.g. ex. ex. ex. 
” Bril. Violet B. ex. g ex. ex. V.g. 
) Red Violet ex. g. ex. ex. ex. 
3 Bril. Violet 2 R. ex. g. ex. ex. V.g. 
. Orange ex. V.g. ex. ex. ex. 
Blue ex. ex. /v.g. ex. ex. ex. 


Celatene Fast Light Yellow, Cel. Fast Light Brown, and Cel. Orange redden on soaping, but 
this is removed by a weak sour. 


Celatene Red Violet is the fastest member of the series to light 
and after 6 months’ exposure of light shades, only a slight fad- 
ing was noticed, while darker shades required twice this period 
of exposure. This is equal to that of the best vat dyes on cotton. 
Celatene Fast Light Yellow and Fast Light Brown approach this 
fastness, and even tints of the Yellow are unchanged after 6 
months’ exposure. Heavier shades are reddened by 10 months’ 
exposure. Under the same exposure the brown shows only a 
slight fading, which is equal to any of the fast vat colors of similar 
shade. The light fastness of Celatene Brilliant Violet 2R is 
similar to that of Caledon Brilliant Purple RR (Indanthrene 
Brilliant Violet RR or Ponsol Violet RR) on cotton. The shade 
fades slightly and is redder. From this we might assume that 
the composition of the Celatene Brilliant Violet 2R is similar to 
that of the Caledon dye, which is dichloroisodibenzanthrone. 

Celatene Brilliant Violet B withstands about 6 months’ ex- 
posure, when it becomes redder. This compares favorably with 
Caledon, Algol or Indanthrene Brilliant Violet R (4, 8-dianisoyl- 
diamino-1, 5-dihydroxyanthraquinone) on cotton. Celatene Or- 
ange is browner after 2 months’ exposure but then remains 
almost unchanged. Medium shades of Celatene Red B and Blue 
are not faded by several months’ exposure. Celatene Yellow and 
Black are the poorest of the products, as regards light fastness, 
as both are distinctly browner after a month’s exposure. Light 
shades of these colors have an.excellent fastness to washing, but 
deeper shades are not as good. All are fast to chlorine except 
Celatene Blue, but this shade is restored by treatment with a 
dilute solution of hydrosulfite. 


304 ACETATE SIG 


The Azonine Direct Dyes and Azonine SF 


Another brand of dispersol dyes are the Direct Azonines of 
the Cassella Company. This is the second group of Azonine dyes 
to be considered as we also had a group under this brand in the 
developed colors. The Direct Azonines are entirely different from 
those previously discussed and are suitably prepared dispersions 
of insoluble dyestuffs which have an affinity for acetate silk. In 
applying these dyes the acetate silk should be scoured as in Method 
No. 5 and is then ready to enter the dye bath, prepared as in 
Method No. 79. While Azonine SF is diazotized and developed 
on the fiber, it is applied by the dispersol method. Also see the 
application of Azonine bases for development by means of a 
tetralin-soap bath, as in Method No. 65 under the Developed 
Colors, Chapter XVII. 

Method No. 79: The Direct Azonines on Acetate Silk. Azonine 
Direct Yellow 2R paste, Azonine Direct Red G paste, Azonine 
Direct Violet R paste and Azonine Direct Blue B paste, are dis- 
solved with the addition of approximately the same weight of 
soap as of dye in boiling very soft water. This concentrated solu- 
tion is strained into the dye bath, previously heated to 60 or 70° C. 
(140 or 160° F.). For light shades it is advantageous to add 
sufficient soap to the bath to bring the total soap content up to 6 
to 8 ounces per 10 gallons of dye bath. In case hard water is 
used, it is best to replace the soap with monopol soap or a similar 
product which is not precipitated in hard water. The dyes level 
well and the wet out acetate silk is usually entered into the dye 
bath at about 60 to 70° C. (140 to 160° F.) and dyed at this 
temperature for 30 or 40 minutes, without any further addition, 
and then rinsed well. 

Method No. 80: Azonine SF on Acetate Silk. Azonine SF is 
dissolved in boiling water containing twice the weight of soap as 
of dye to be dissolved. This solution is strained into the dye bath 
previously heated to 60 to 70° C. (140 to 160° F.). The scoured 
acetate silk is entered at this temperature, worked for about 45 
minutes, and rinsed. 

Method No. 80-A: Diazotizing SF on Acetate Silk. Diazotize 
for 15 or 20 minutes in a cold bath containing 2.5 ounces of 


MISCELLANEOUS DYES 305 


sodium nitrite and 8 ounces of 34° Tw. hydrochloric acid, per 10 
gallons of liquor. Rinse well and develop immediately. 

Method No. 80-B: Developing Azonine SF on Acetate Silk. 
The developing bath is prepared by first dissolving a pound of 
Developer ON in 2 to 3 gallons of water containing 2 pounds of 
sodium acetate. This concentrated solution is added to the de- 
veloping bath in such proportions that when ready for use it will 
contain about 2.5 ounces of Developer ON per 10 gallons of bath. 
In other words, 1 pound of Developer ON and 2 pounds of 
sodium acetate will make up a developing bath of 64 gallons. The 
wet, rinsed, diazotized acetate silk is immediately entered into 
this bath at 45 to 50° C. (113 to 122° F.) worked for 20 or 30 
minutes and then rinsed well. 


TABLE. LV. 
THE Direct AZONINES ON ACETATE SILK 
Color Dyes 
Greenish- Yellow 0.75% Azonine Direct Yellow 2R paste and 


.14% Azonine Direct Blue B paste. 
.7%  Azonine Direct Yellow 2R paste, 
.6% Azonine Direct Blue B paste, and 
.2% Azonine Direct Red G paste. 
.14% Azonine Direct Yellow 2R paste, 
7% _ Azonine Direct Blue B paste, and 
.4%  Azonine Direct Red G paste. 
.38% Azonine Direct Yellow 2R paste, 
.15% Azonine Direct Blue B paste, and 
Azonine Direct Red G paste. 
.0% Azonine Direct Yellow 2R paste, 
.2% Azonine Direct Blue B paste, and 
.7% Azonine Direct Red G paste. 

3%  Azonine Direct Yellow 2R paste, 
.3% Azonine Direct Blue B paste, and 
7% _ Azonine Direct Red G paste. 

.3% Azonine Direct Yellow 2R paste and 
.3% Azonine Direct Blue B paste. 
.0% Azonine Direct Blue B paste and 
.7% _ Azonine Direct Red G paste. 


Medium Bluish-Gray 


Medium Reddish-Tan 


Light Tan 


Medium Brownish-Tan 


Dark Chestnut Brown 


Medium Green 


Dark Bluish-Gray 


SAWWRWWONFOOOOCOCOHOCS 
ww 
9S 


When applied by Methods No. 79 and No. 80 these dyes level 
well and give colors of very good fastness to rubbing, washing 
and light. As they do not appreciably stain cotton, they may 
readily be used in obtaining two color effects on unions contain- 
ing acetate silk and cotton. Good bright shades are obtained 


306 ACETATE SILK 


with 6 to 7.5 per cent of Azonine Direct Yellow 2R paste, Azon- 
ine Direct Red G paste, Azonine Direct Blue B paste, or a good 
black with 2 per cent Azonine SF diazotized and developed with 
Developer ON. Table LV gives a few formulas for compound 
shades. Azonine Direct Yellow 2R is probably an aminoazo 
derivative, perhaps the same as the “Yellow R Paste for Acetate 
Silk” of Badische. 


The “Extra Pastes for Acetate Silk” 


The Badische Company now offer a line of dispersol dyes for 
acetate silk under the above name. The following are available: 
Yellow 3G Paste for Acetate Silk, Yellow R Paste for Acetate 
Silk, Yellow RR Paste for Acetate Silk, Orange Extra Paste for 
Acetate Silk, Pink R Extra Paste for Acetate Silk, Pink B Extra 
Paste for Acetate Silk, Red R Paste for Acetate Silk, Red Violet 
Extra Paste for Acetate Silk, Violet B Extra Paste for Acetate 
Silk, and Blue Extra Paste for Acetate Silk. 

At the present time the constitution of these products is not 
generally known, but the Yellow 3G Paste may be a derivative of 
nitroaniline: Yellow R Paste an aminoazo derivative ; and Orange 
Extra Paste, Rose R Paste, Red-Violet Extra Paste, and Blue 
Extra Paste aminoanthraquinone derivatives. This, together with 
the method of application indicates that they are really dispersol 
products. It is not known whether they are related to British 
Patent No. 204,280, of the same company or not. When applied 
to acetate silk unions in light shades, the cotton usually remains 
unstained, but heavier dyeings generally tint the cotton somewhat. 
Yellow R Paste for Acetate Silk is only recommended for self- 
shades ; for compound shades Yellow 3G or Yellow RR Pastes for 
Acetate Silk should be used. 

Method No. 81: “Extra Pastes”’ on Acetate Silk. The paste is. 
first diluted with water at the ordinary temperature and mixed 
well. This is sieved into a dye bath containing about 2 or 3 grams 
per liter of green olive oil soap, depending upon the depth of 
shade, or an equivalent amount of Turkey-red oil, Brilliant Mono- 
pole oil, or a similar preparation. For light or medium shades, 
enter the goods into the lukewarm dye bath and dye for a half 


MISCELLANEOUS DYES 307 


to one hour at 50 to 70° C. (122 to 158° F’.). Darker shades may 
be entered at a higher temperature. The dyed material should be 
rinsed and brightened in a cold formic or acetic acid bath. The 
same method is used for piece dyeing. 


The Cibacete Dyes 


The Cibacete dyes of the Ciba Company, while not in the usual 
dispersol paste form, are applied by the dispersol method and 
undoubtedly belong to this general classification. They are in 
powder form and of exceptionally high tinctorial power, one to 
two per cent of the dyestuff giving good medium heavy shades. 
They have good fastness to washing and light, and are applied by 
the usual simple dispersol process. They leave cotton and the 
older rayons unstained in most instances but Cibacete Scarlet G 
stains cotton more than the other members of the group. 

The Cibacete dyes are prepared for the dye bath by emulsify- 
ing them with sodium or ammonium sulforicinoleate or soap. If 
hard water must be used in the dye bath, soluble oil should be 
substituted as the emulsifying agent. The quantity of emulsifying 
agent to be used depends entirely upon the volume of the dye 
bath. In general, 2 to 4 grams per liter of dye bath is used. This 
is dissolved in about 20 times its weight of water at 50 or 60° C. 
(122 or 140° F.) and the dyestuff added. The mixture is stirred 
vigorously until solution is complete and then screened into the 
dye bath. The dyeing is usually complete in about 45 minutes at 
%0 to 75° C. (68 to 167° F.), when the shade 'can be brightened 
with acetic acid. 


The Cellacete Dyes 


The Cellacete dyes of Kalle are paste products which are merely 
diluted with hot water for use. They appear to be dispersol prod- 
ucts and are applied in a mildly alkaline soap bath. Some mem- 
bers of the group, for instance Cellacete Yellow G and R, may be 
developed with B-naphthol or diamines to give scarlet or bordeaux 
shades, and Cellacete Orange R gives a deep violet to black shades 
on development. The present members of the group are: Cell- 
acete Blue F, Cellacete Orange G, 2G, and R, Cellacete Red G, 


308 ACETATE SILK 


Cellacete Rose R, Cellacete Yellow G, 5G, 6G, and R. Asa class 
the’ fastness of the resulting colors to water and washing is satis- 
factory. The light fastness varies somewhat between the various 
members of the group, but on the whole is satisfactory. 


Celanthrene Dyes 
The Newport Chemical Works are preparing a line of Celan- 
threne dyes for acetate silk? which will probably include the fol- 
lowing when complete: 


Celanthrene Blue Celanthrene Fast Light Yellow 
Celanthrene Violet B Celanthrene Yellow 
Celanthrene Red Violet Celanthrene Gold Orange 
Celanthrene Brilliant Red Celanthrene Fast Light Brown 
Celanthrene Red B Celanthrene Black 


The Celanthrene dyes are prepared paste dispersions of anthra- 
quinone derivatives and correspond closely to the Celatene dyes 
of Scottish Dyes. They are, of course, primarily intended for the 
dyeing of acetate silk and as a class do not stain cotton. They 
are not recommended for dyeing unions of wool or true silk 
with acetate silk, as they stain both true silk and wool. However, 
the staining of these animal fibers appears to be largely due to a 
mechanical absorption of the dyestuff, as the colors obtained are 
not fast to washing. On acetate silk they have excellent general 
fastness properties and can be used in connection with vat dye- 
stuffs to produce two colored effects on cotton-acetate silk unions. 
Their fastness to light is of particular interest in this connection. 
They are readily applied by the usual methods for dispersol prod- 
ucts. 

The goods should be wet out with Isomerpin or some other 
suitable reagent in aqueous solution, and then entered into a warm 
20 or 40 to 1 dye bath. This bath may be cloudy at the start but 
gradually clears as the dyestuff is taken up by the fiber. The tem- 
perature is gradually raised, during about 30 minutes, to 77 or 
82° C. (170 or 180° F.). The dyeing is continued at this temper- 
ature until the desired shade is obtained or the bath is fairly well 
exhausted. This usually requires 30 to 45 minutes longer, and an 
addition of Glauber’s salt may be made to aid the exhaustion. 
After the dyeing the material is lifted, rinsed, and dried in the 


MISCELLANEOUS DYES 309 


usual manner. For very dark shades a standing bath may be an 
advantage, in which case an addition of about 70 per cent of dye- 
stuff is made to replenish the bath. While the Celanthrene dyes 
can be combined with each other to give a wide variety of combi- 
nation shades, in the application of these combination shades it is 
advisable to start the dyeing at a temperature below 49° C. 
(120° F.). 

The fastest member of the series is Celanthrene Red Violet. 
Next in line are Celanthrene Fast Light Yellow and Celanthrene 
Fast Light Brown. The Celanthrene Violets compare favorably 
with the various types of vat violets on the market, with which they 
are probably closely related. The remaining members of the series 
all have very good fastness to light. Celanthrene Yellow and Cel- 
anthrene Black are the poorest members of the class but still show 
quite good fastness. 


Newport Dyes 

Among other products which may be applied to acetate silk by 
the dispersol method may be mentioned Newport Azo Sudan, Azo 
Yellow B, Azo Orange, Azo Red, and Azo Blue. It is only neces- 
sary to dissolve these water-insoluble products in Turkey-red oil, 
or other suitable, water-soluble solvent, and add this solution to 
the dye bath. When Turkey-red oil is used as the solvent, the 
dispersol dyestuff is applied in a soapy dye bath in about the same 
manner as the S. R. A. dyes. Azo Sudan, Azo Yellow B, and Azo 
Orange give shades of excellent strength and brilliancy but have 
a certain tendency to crock. However, this crocking may be en- 
tirely remedied by working the dyed acetate silk in a cold bath 
containing 2 per cent of sodium hydroxide, on the weight of the 
goods, for 20 minutes. This treatment does not seriously weaken 
the shades but no doubt saponifies the acetate silk to some extent. 
Azo Red and Azo Blue do not crock and therefore this severe 
after-treatment is unnecessary. These colors are only moderately 
fast to light but wash well. | 

A number of the Anthrene, as well as other water insoluble vat 
dyes of suitable constitution may also be applied to acetate silk 
by the dispersol method, after dissolving the dyestuff in sulfonated 


310 ACETATE SILK 


oil or other suitable medium for dispersion. Indigo as well as 
some of its compounds in the unreduced state have been obtained 
in the colloidal condition by means of the dispersol process, but 
most of them have only a very slight affinity for acetate silk. This 
is particularly true of indigo itself. 


Increasing the Light Fastness of Colors on Acetate Silk 


The fastness to light? of many of the more or less light fugitive 
colors on acetate silk may be very considerably improved by the 
presence on the fiber of certain colorless organic compounds of a 
basic nature, such as aniline, B-naphthylamine, benzidine, etc. Cer- 
tain dialkylanilines, such as dimethylaniline, are particularly effec- 
tive. These products are applied by the dispersol method, that 
is, they are dissolved in a dispersing agent, such as sulforicinoleic 
acid or Turkey-red oil, and this is either added to the dispersol dye 
bath, or applied in a subsequent bath. 

Apparently as much as about 2 per cent of the dialkylaniline is 
taken up by the silk, either in solid solution or chemical combina- 
tion, due to its high affinity for such basic compounds. As much 
as 5 per cent of the product appears to have been used in some 
instances. Where it is all combined in the acetate silk fiber, there 
is no noticeable odor, but the odor of an excess may be detected. 
This would apparently indicate a chemical combination with the 
acetate silk of that portion taken up by the fiber. Their protective 
action is probably based upon their absorption of the ultra-violet 
rays as spectroscopic investigation shows that after this treat- 
ment, the acetate silk absorbs all light rays below about 3400 A. U. 
The dialkylanilines are readily prepared for use by the dispersol 
method by boiling them with about their own weight of Turkey- 
red oil. This solution is added directly to the aqueous bath. 

This process is covered by British Patent No. 243,841 of 1924 
to G. H. Ellis and the British Celanese, Ltd., which states that 
the poor light-fastness properties of the colors given by certain 
dyes on acetate silk, and even those of good light fastness, may 
be improved by treating the dyed material with one or more sim- 
ple amino or substituted amino compounds, such as aniline, alky- 


MISCELLANEOUS DYES 311 


lanilines and alkylphenylenediamines, for example tetraethyl- 
phenylenediamines. The effectiveness of the treatment increases 
with increased alkylation of the treating compound. The amino 
compounds may be applied in aqueous solution in the form of the 
free base in any suitable media; as the hydrochloride or other 
soluble salt; or they may be solubilized or dispersed by suitable 
solubilizing agents such as those covered by patents No. 219,349, 
No. 224,925, No. 242,393, or No. 242,711. It is preferred not 
to use amines which are susceptible to air oxidation, such as di- 
phenylamine, p-aminophenol, and p-phenylenediamine. The proc- 
ess is more effective upon the azo dyes than with those of any other 
class. 

As an example, 100 pounds of acetate silk may be dyed in any 
suitable manner with an aqueous hydrochloric acid solution of 
benzeneazo-a-naphthylamine. Then 3 pounds of diethylaniline hy- 
drochloride are dissolved in water and added to a fresh aqueous 
bath, and the dyed material worked in it until no more amine is 
absorbed. The resulting shade has a greatly increased fastness to 
light. 


References 


*P. Castan, Arch. sci. phys. nat. (5), 7, 196-204 (1925). 

*G. H. Ellis, J. Soc. Dyers and Colourists 41, 98-9 (1925) ; and 
J. Soc. Dyers and Colourists 42, 184-6 (1926). 

*P. H. Stott, American Dyestuff Reporter 16, 21 (1927). 


CHAP TER AX I 


THE PATENTS COVERING THE PREPARATION AND 
APPLICATION OF THE DISPERSOL DYES TO ACE- 
TATE SILK AND OTHER FIBERS 


WHILE the dispersol dyes are comparatively new products, the 
first patent covering them having been granted on December 21, 
1922, there is at present a rather large number of patents covering 
their preparation and application. This merely indicates the 
amount of research that is being done on this one phase of acetate 
silk dyeing, which in turn emphasizes the growing importance of 
the whole acetate silk industry. 

The following abstracts from the patent literature covering the 
dispersol dyes are of interest in that they give more definite in- 
formation than is available from any other source, as to the com- 
pounds used in, and the constitution of, the dispersol dyes, as well 
as the methods of manufacture and application. The patents are 
given in their numerical order, which appears to be some index 
as to the sequence of applications. Apparently the first patent on 
this subject is British Patent No. 207,711. 

British Patent No. 207,711, December 21, 1922, to the British 
Dyestuffs Corporation, J. Baddiley, and W. W. Tatum, covers the 
use of anthraquinone dyes containing carboxylic groups but no 
sulfonic groups, on acetate silk. Suitable dyes are those obtained 
by condensing salicylic acid p-sulfonyl chloride with diamino- 
anthraquinones, as described in British Patent No. 201,610, or by 
condensing haloanthraquinones with a suitable aminocarboxylic 
acid, such as anthranilic acid. The dyeing is effected in a neutral 
or slightly alkaline bath, with a subsequent addition of salt or 
acid to aid exhaustion. These products give blue shades which are 
unobtainable with azo compounds, and they have the excellent 
fastness to light and washing common to the anthraquinone dye- 
stuffs. In this manner 1,5-dichloroanthraquinone with anthranilic 
acid dyes acetate silk directly a reddish-violet shade (Duranol 


312 


PREPARATION AND APPLICATION PATENTS: 318 


Violet 2R?). 4-Brom-1-methylaminoanthraquinone with anthran- 
ilic acid gives direct reddish-blue shades, while dichloroanthrarufin 
with anthranilic acid gives greenish-blue shades (Duranol Blue 
G?). 1,4-Diaminoanthrarufin, and diaminoanthrarufin with the p- 
sulfonyl chloride of salicylic acid, and the dinitro-1, 5-dichlo- 
roanthraquinone and anthranilic acid are also mentioned. The 
latter product is reduced. Undoubtedly this patent covers some of 
the Duranol dyes and probably some of the Celatenes. Also see 
British Patents No. 225,678 and No. 227,923, and United States 
Patent No. 1,574,748. 

From the above there does not appear to be any reason why 
these products could not be applied by the usual “direct” method 
used for-applying the acid and mordant type of dyes to acetate 
silk. However, as might be expected, these anthraquinone com- 
pounds are not very soluble in water, although they are not exactly 
insoluble. For this reason they are well adapted for application 
by the dispersol method, where their slight solubility in water 
allows them to react readily with the fiber and the large surface 
of the dispersol dyestuff phase allows a very rapid renewal of 
the dyestuff removed from solution by the fiber. Then too their 
comparatively slight solubility in water is a factor in favor of 
dyeing acetate silk.® 

British Patent No. 201,610, April 28, 1922, to the British Dye- 
stuffs Corporation, J. Baddiley, and W. W. Tatum, which is men- 
tioned in the above patent No. 207,711, and also in No. 225,678, 
covers acid and acid-mordant wool dyes of the anthraquinone 
series, some of which may also have an affinity for acetate silk. 
This patent states that wool dyes of excellent fastness to milling 
and washing are obtained by condensing the amino derivatives of 
anthraquinone with the sulfochlorides of salicylic acid, either with 
or without a condensing agent. For example: a blue dyestuff is 
produced by heating a mixture of 27 parts of tetraaminoanthra- 
quinone, 25 parts of salicylic sulfochloride, 17 parts of fused 
sodium acetate, and 210 parts of nitrobenzene at 135° C. for 3 
hours, freeing the product from nitrobenzene by steam distillation 
and precipitating the dyestuff with salt. 


"See Chapter VIII. 


314 ACETATE SICK 


British Patent No. 203,051, May 31, 1922, to Imray, for the 
Ciba Company, and United States Patent No. 1,586,911, to W. 
Moser (June 1, 1926), assigned to the same company, covers the 
preparation of 2,3-diaminoanthraquinone from 2-amino-3-brom- 
oanthraquinone by heating it with ammonia, or a liquid containing 
ammonia, in a closed vessel at 170 to 190° C., with or without the 
addition of a catalyst. The product dyes acetate silk a pale yel- 
lowish-brown color. 

According to British Patent No. 211,720 to the British Dye- 
stuffs Corporation, J. Baddiley, and A. Sheperdson, March 8, 
1923, acetate silk may be dyed yellow to blue shades in an aqueous 
dye bath containing aminoanthraquinone dyes in colloidal solution 
or suspension. The presence of emulsifying agents, such a Turkey- 
red oil, in the dye bath is advantageous. In this manner 1-amino- 
anthraquinone gives a yellow shade; 1-amino-2-methylanthraqui- 
none gives a yellowish-orange ; 1-methylaminoanthraquinone a red ; 
1, 4-diaminoanthraquinone a violet; 1, 5-diaminoanthraquinone a 
red ; diaminoanthrarufin a blue; 1,4-aminohydroxyanthraquinone a 
crimson; and diaminoanthrarufin, when methylated in one or both 
of the hydroxy groups, a sky blue shade. 

F. Bayer & Company in British Patent No. 214,246, April 14, 
1923, cover the dyeing of acetate silk with solutions prepared by 
dissolving unsulfonated dye bases of the triphenylmethane, anthra- 
quinone, or other series in glycerol, epichlorohydrin, ethylene 
chlorohydrin, or other organic solvent and diluting this solution 
with water to obtain the base in a finely divided state. Its colliodal 
condition may be improved by adding glue, gelatin, or Turkey-red 
oil to the bath. For instance: Methyl Violet 6B base, China Green 
base (p, p’-tetramethyldiaminotriphenylcarbinol anhydride), or 
Alizarin Geranol base, can be dissolved in ethylene chlorohydrin, 
diluted with water, glue or Turkey-red oil added, and the acetate 
silk dyed at 50 to 60° C. (122 to 140° F.). 

The British Patent No. 214,765, February 8, 1923, to H. A. E. 
Drescher, J. Thomas, and Scottish Dyes, states that anthraqui- 
noneimides of dibasic acids are obtained by heating a halogenan- 
thraquinone with an imide of a dibasic acid in the presence of 
copper and an acid absorber, or with copper and a metal imide salt. 


PREPARATION AND APPLICATION PATENTS 315 


The imides yield aminoanthraquinones upon hydrolysis, as for 
instance with sulfuric acid. It describes the preparation of numer- 
ous compounds, including 1-phthalimidoanthraquinone, 1, 5-diph- 
thalimido-, 1, 5-diamino-, 1-chloro-5-phthalimino-, and 1-chloro-5-_ 
aminoanthraquinones, 4-phthalimido and 4-amino-1-methylamino- 
*-bromoanthraquinone, 1-phthalimido-2-nitro- and 1-amino-2-ni- 
troanthraquinones. This patent is mentioned in connection with 
British Patents No. 230,116 and No. 231,206, etc., which cover 
dispersol products ; and United States Patent No. 1,528,470 covers 
the preparation of the compounds mentioned. 

British Patent No. 219,349, January 27, March 17, and May 22, 
1923, to British Celanese, Ltd., formerly the British Cellulose and 
Chemical Manufacturing Company, and G. H. Ellis gives con- 
siderable detail regarding the dispersol dyes, and as this company 
manufactures the S.R.A. dyes, we may assume that it very largely 
covers these products. According to this patent, dyes which are 
capable of coloring acetate silk, but which are too insoluble in 
water to be applied by the usual methods, may be treated with the 
higher fatty acids, or their derivatives which contain salt-forming 
groups, such as sulforicinoleic, oleic, stearic or palmitic acid, or 
their alkali or ammonium salts, to form colloidal solutions or dis- 
persions and thus become sufficiently soluble or dispersed to allow 
their use in the commercial dyeing of acetate silk in aqueous dye 
baths. 

A wide range of insoluble products may be applied by this 
method. The simple aromatic amino bases may be applied in this 
manner for the production of insoluble azo colors on the fiber, and 
they may be used either in the impregnating or developing bath or 
in both. Many unsulfonated azo dyes, unreduced dyestuffs of the 
Indophenol and Indigoid classes, basic derivatives of the anthra- 
quinone series, and the color bases of diphenylmethane, triaryl- 
methane, oxazine, azine, and thiazine dyes may be also be dispersed 
by this method. In general, most of the dyes or compounds must 
be in the form of free bases, and should contain no sulfonated 
groups for the reasons previously given. Other substituent groups, 
such as primary, secondary, and tertiary amino groups, nitro, 
nitroso, hydroxy, methoxy, or halogen groups, may be present and 


316 ACETATE SILK 


where a free primary aromatic amino group is present, it may be 
diazotized and developed on the fiber by the methods given under 
the Developed Colors, Chapters XVI and XVII. 

To prepare the soluble product, the dyestuff or other organic 
compound to be used, is mixed, with or without heat, with the 
free fatty acid, or its alkali or ammonium salt, the resulting mix- 
ture being subsequently diluted with water or a solution of alkali, 
boiled, and filtered through cloth into the dye bath, which may be 
either neutral, acid, or alkaline. If desired, suitable dyeing materi- 
als may be converted into “solid solutions” or complexes by heat- 
ing them with the appropriate oily body followed by the requisite 
treatment to render them fit for transport. 

Dyes dispersed in this way may be used, with or without the 
addition of other dyestuffs not deleteriously affected by the solu- 
bilizing agents, for dyeing, printing, or stencilling fabrics contain- 
ing acetate silk in unions with other fibers or threads, the non- 
sulfonated azo dyes being preferentially fixed by the acetate silk, 
leaving the cotton, wool, silk and regenerated rayons unstained or 
but slightly stained. These latter fibers may be subsequently or 
simultaneously dyed with suitable dyestuffs which have no affinity 
for the acetate silk.. The Indophenol type of dyes are very suitable 
for blue and violet shades. Benzeneazobenzeneazo-B-naphthol 
(Sudan III), 4-nitro-2-methoxybenzene-1-azodiphenylamine, and 
aminoazonaphthalene are also mentioned. 

For example, pink and red shades may be obtained on acetate 
silk by treating 4-nitro-2-methoxybenzene-1-azodimethylaniline 
with sufficient ‘oleic acid to dissolve it on heating, and then pouring 
the hot solution into hot water containing enough ammonia or 
sodium carbonate to neutralize the fatty acid. This mass is filtered 
into the dye bath. 

An orange shade on 100 kilos of acetate silk may be obtained by 
heating a kilo of finely ground p-nitrobenzeneazodiphenylamine 
with 10 liters of 50 per cent sodium sulforicinoleate. This is di- 
luted with boiling water and boiled, after which it is added to the 
30 to 1 dye bath and the yarn dyed in the usual manner, raising 
the temperature to 65 to 75° C. (147 to 167° F.) if necessary. 

A scarlet shade on the same quantity of acetate silk may be 
obtained with 1.5 kilos of aminoazobenzene and 15 liters of 50 


PREPARATION AND APPLICATION PATENTS 317 


per cent sodium sulforicinoleate. After dyeing, rinse the stock 
and diazotize. Then rinse again and develop in a solution contain- 
ing 3 kilos of dimethylaniline in 20 liters of 50 per cent sodium 
sulforicinoleate, prepared in the same manner as the red dye above. 

In a somewhat similar manner 25 kilos of a 50-50 acetate silk- 
cotton union fabric may be dyed, the acetate silk a bluish-red and 
the cotton a blue shade. Heat 250 grams of finely powdered 2, 4- 
dinitrobenzene-1-azodiethylaniline for 10 minutes at 100° C. (212° 
F.) in 5 liters of 50 per cent sodium sulforicinoleate. This dis- 
persol dye compound is diluted with boiling water, boiled, filtered 
into a 750 liter dye bath, and the union entered. When the acetate 
silk has reached the desired shade, the material is removed from 
the bath, rinsed in warm water and the cotton dyed a blue shade 
in a dye bath containing 375 grams of Chlorazol Fast Blue 2B. 
Possibly Diamine Fast Blue FFB, Direct Fast Blue FF or Sola- 
mine Blue FF could also be used for the cotton. 

The Indophenols may be applied by first converting them into 
water-soluble bodies by treatment with fatty or sulfonated acids 
giving water soluble sodium or ammonium salts, such as sulforicin- 
oleic acid. Glue may also be used. For instance, 500 grams 
of diethyl-p-aminophenol-1,4-naphthoquinonemonoimide may be 
ground with 10 liters of water and this added to 2000 liters of 
water containing 4 kilos of glue. The dyeing is carried out at 40 
to 70° C. (104 to 158° F.). The glue may be omitted if the dye- 
stuff is first dissolved in a suitable solvent and poured into water 
to obtain a fine suspension. 

In British Patent No. 222,001, November 27, 1923, to A. J. 
Hall and Silver Springs Bleaching and Dyeing Company, it is 
stated that acetate silk may be dyed yellow to red shades of excel- 
lent fastness, especially to washing, light and chlorine, by means of 
2, 4-dinitrochlorobenzene derivatives, produced by condensing 2, 4- 
dichlorobenzene with aromatic compounds containing one or more 
amino groups, but no sulfonic acid groups. For instance 2, 4-dinitro- 
diphenylamine and its 2’- or 4’-hydroxy- derivative, 2, 4-dinitro-2’- 
hydroxydiphenylamine, or 2, 4-dinitro-4’-hydroxydiphenylamine ; 
the carboxyl derivatives 2, 4-dinitro-2’-carboxyldiphenylamine ; 
and 2, 4-dinitro-4’-carboxyldiphenylamine ; 2, 4-dinitro-4’-aminodi- 


318 ACETATE SILK 


phenylamine, 2, 4-dinitro-4’-acetylaminodiphenylamine, and 2, 4- 
dinitro-N-methyldiphenylamine, may be used for dyeing acetate 
silk directly from a solution or dispersion in water at THES 
(167° F.). Turkey-red oil, soap, or ammonia may be added to 
the bath. Cotton or artificial silk are not stained. 

In British Patent No. 224,077, October 19, 1923, and United 
States Patent No. 1,534,019, April 21, 1925, to the British Dye- 
stuffs Corporation, Baddiley, Hill, Lawrie, Shepherdson, and 
Swann, it is proposed to disperse water-insoluble, or nearly in- 
soluble dyes, which have an affinity for acetate silk, in the con- 
densation products of naphthalene or naphthalenesulfonic acids 
with formaldehyde. Dyes such as those specified in British Patent 
No. 211,720 are suitable and such dispersing agents may be used 
to dye acetate silk a yellowish-red with the monoazo dye prepared 
from diazotized p-nitroaniline and diphenylamine; or violet-red 
with a dispersion of 1, 4-diaminoanthraquinone. These products 
may be mixed with direct cotton dyes for use on unoins, etc. Also 
see British Patent No. 246,984. Pastes containing these protective 
colloids and suitable dyes may be evaporated to dryness and ground 
to a powder for shipment or storage. 

Excellent black shades on acetate silk may be obtained without 
double diazotization and double coupling by the method covered in 
British Patent No. 224,359 of 1923 to Lawrie, Blackshaw, and the 
British Dyestuffs Corporation. In this process bases such as 
a-naphthylamine, benzidine, toluidine and , p’-diaminodiphenyl- 
amine are applied to the fiber in the free condition, or are produced 
on the fiber in this state by known methods, e.g., hot dispersions in 
such liquids as aqueous alcohol or Turkey-red oil. A “basic” salt 
of the base may be used and the base subsequently liberated on 
the fiber by means of sodium carbonate. It can then be diazotized 
and developed with B-hydroxynaphthoic acid or resorcinol in a 
slightly acid bath. The fact that reddish azo dyes are ultimately 
obtained from the same base when they are applied in the ordinary 
manner, that is, without the liberation of free base, is said to be 
due to the small amount of dyestuff on the fiber, whereas by this 
process a much larger quantity of the base and consequently a cor- 
respondingly larger amount of dyestuff is present on the acetate 
silk. 


Pee ON AND APPLICATION PATENTS 319 


In British Patent No. 224,681, October 11, 1923, to British 
Celanese, Ltd., Ellis, Stevenson, and Croft, it is stated that acetate 
silk may be dyed, printed or stencilled by means of non-sulfonated 
pyrazolone compounds, particularly the non-sulfonated azo deriva- 
tives. For instance, azo dyes prepared by coupling unsulfonated 
diazo compounds with 1-phenyl-3-methyl-5-pyrazolone, benzene- 
azo-1-phenyl-3-methyl-5-pyrazolone, 1,3-dimethyl-5-pyrazolone, p- 
methoxybenzeneazo-1-phenyl-3-methyl-5-pyrazolone and dimethyl- 
p-aminobenzeneazobenzeneazo-1-phenyl-3-methyl-5.-p yrazolone. 
The dyes may be used in solution with sodium hydroxide, or dis- 
solved in an organic solvent miscible with water and then mixed 
with water, or may be dispersed in sulforicinoleic acid or other sol- 
_ubilizing or dispersing agents, as described in British Patent No. 
219,349. These dyes may be used in conjunction with others for 
dyeing mixed goods containing acetate silk together with cotton, 
silk, or wool, usually giving yellow to orange shades. United 
piatesstatent No. 1,600,277, September 1, 1926, to Ellis, Stev- 
enson and Croft; and Canadian Patent No. 260,530, May 4, 1926, 
to the same inventors, cover this process. 

In British Patent No. 224,925, May 22, 1923, to Ellis and the 
British Cellulose and Chemical Manufacturing Company, they 
state that it is of some advantage to substitute carbocyclic com- 
pounds containing salt-forming groups for the sulforicinoleic acid 
compounds specified in British Patent No. 219,349, as the solvent 
or dispersing agent. Suitable compounds are given as naphthenic 
acids and naphthalenesulfonic acid or other carboxylic or sulfonic 
acids of the cycloparaffins or phenols; and the sulfonic, carboxylic, 
and phenolsulfonic acid derivatives of the benzene, naphthalene, or 
anthracene series. In certain cases it may be of advantage to use 
the above in combination with the older reagent ; 7.e., sulforicinoleic 
acid. For example, one pound of m-nitrobenzeneazodiphenylamine 
is finely ground and heated with 9 pounds of naphthenic acid until 
homogenous, sufficient sodium hydroxide being then added to give 
the product a slightly alkaline solution. After filtration, this is suit- 
able for direct addition to the acetate-silk dye bath. A blue is 
obtained in a similar manner with 1-methylamino-4-p-tolylamino- 
anthraquinone. Also see German Patent No. 303,121 and United 
States Patent No. 1,610,961. 


320 ACHI ATH Sins 


British Patent No. 225,678, October 23, 1923, another addition 
to British Patent No. 201,610, and to the same inventor, describes 
the manufacture of other acetate silk dyes by substituting the sul- 
fochlorides of other o-hydroxycarboxylic acids, such as o-cresotic 
acid, for the salicylic sulfochlorides of the principal patent. For 
instance, ten parts of 1, 4-diaminoanthraquinone, either dissolved 
or suspended in 60 parts of acetic acid are stirred with 12 parts of 
o-cresotic sulfochloride at 60° C. for 4 hours, during which time 4 
parts of anhydrous sodium acetate are gradually added. After the 
separation of the dye, it is converted into its sodium salt, the 
solution filtered from the uncondensed diamine, and the dyestuft 
salted out. This product dyes wool a bluish-red shade and has a 
high affinity for acetate silk (Duranol Red 2B?). Also see British 
Patent No. 207,711. 

British Patent No. 227,183, October 19, 1923, addition of British 
Patent No. 219,349, to Ellis and the British Cellulose and Chemical 
Manufacturing Company, covers the use of vat dyes of the anthra- 
quinone class, such as Indanthrene, Cibanone, Algol, etc., stabilized 
as in the main patent. For example, one pound of Algol Pink R 
(1-benzoylamino-4-hydroxyanthraquinone) is made into a paste 
with 9 or 10 pounds of 50 per cent sodium Turkey-red oil pre- 
viously heated to 90° C. (194° F.) and the heating continued until 
the dye is dissolved. This paste is diluted with a boiling 3 to 5 per 
cent solution.of neutral soap, and the mixture added to the 300 to 
500 gallon dye bath. The above is sufficient to dye 100 pounds of 
acetate silk, after which it is rinsed, dried, etc. It is possible that 
many other vat dyes may be applicable by the same process, as 
for instance, Indanthrene X (N-dihydro-1, 2, 1’, 2’-anthraquinone- 
azine), Indanthrene Bordeaux B (6, 6-dichloro-2, 7-di-a-anthra- 
quinonyldiaminoanthraquinone), Algol Rose B (1-benzoylamino- 
4-methoxyanthraquinone), Algol Scarlet G, Algol Yellow WG 
(1-benzoylaminoanthraquinone), Algol Violet B (1-benzoylamino- 
4,5, 8-trihydroxyanthraquinone), etc. 

British Patent No. 227,923, October 25, 1923, to the British 
Dyestuffs Corporation, J. Baddiley and W. W. Tatum, states 
that acid dyestuffs having an affinity for acetate silk may be pre- 
pared by condensing the 1, 5-dichloro- derivatives of anthraqui- 


\ 
Poe ION AND APPLICATION PATENTS 3821 


none, such as 4, 8-dinitro-1, 5-dichloroanthraquinone, with 2 mole- 
cules of anthranilic acid, and reducing. The value of these dyes 
is enhanced when they contain amino or hydroxy groups in the 
p-position to the aminobenzoic residue. or instance, 4, 8-di- 
phenylaminoanthrarufin-o, o’-dicarboxylic acid (from 4, 8-dichlo- 
roanthrarufin) dyes acetate silk a greenish-blue (Duranol Blue 
G ?); and 4, 8-diphenylamino-1, 5-diaminoanthraquinone-o, o’-di- 
carboxylic acid (from 1, 5-dichloro-4, 8-dinitroanthraquinone, the 
nitro group being reduced with sodium sulfide after condensation ) 
dyes acetate silk a green color. 

British Patent No. 230,116, September 3, 1923, to Scottish Dyes, 
E. G. Beckett, and J. Thomas, covers the production of a purple 
dye for acetate silk from phthalimidoanthraquinone, described in 
British Patent No. 214,765. The nitration of 1-phthalimidoan- 
thraquinone at 15 to 20° C. (57 to 66° F.) in concentrated sulfuric 
acid gives a dinitro derivative which is hydrolyzed by 85 per cent 
sulfuric acid at 85° C. (185° F.) to a dinitro-1-aminoanthraqui- 
none. This upon reduction with soduim sulfide in an aqueous 
sodium hydroxide solution at 80° C. (176° F.) gives triamino- 
anthraquinone, bronze crystals which in aqueous suspension dye 
acetate silk deep purple shades. The triaminoanthraquinone may 
be benzoylated with benzoyl chloride in pyridine or nitrobenzene 
solution to give a reddish-purple crystalline product which dyes 
cotton bluish-red shades fast to washing, bleaching, and light, 
from an alkaline hydrosulfite vat. Possibly the above patent may 
cover Celatene Brilliant Violet B. 

British Patent No. 231,206, March 21 and September 14, 1923, 
to Scottish Dyes, E. G. Beckett, J. Thomas, and J. Tonkin, states 
that acetate silk is dyed greenish-blue to deep blue shades by im- 
mersion in a hot aqueous suspension of hexa-aminodianthraqui- 
nonylthioether, or a dyestuff obtained by the nitration of 1, 5- or 
1, 8-diphthalimidoanthraquinone (see British Patent No. 214,765) 
and subsequent hydrolysis of the product by means of an alkaline 
sulfide. For example, a blue dyestuff is obtained by nitrating 50 
grams of 1, 5-diphthaliminoanthraquinone, dissolved in 500 grams 
of 97 per cent sulfuric acid, for an hour at 30° C. (87° F.) by the 
addition of 62 grams of 80 per cent nitric acid and 50 grams of 


322 ACETATE SILK 


97 per cent sulfuric acid. The product is poured into 5 liters of 
water, filtered, the residue washed free from acid, heated for one 
hour at 80° C. (176° F.) in 1500 cubic centimeters of water con- 
taining 227 grams of sodium sulfide crystals and 35 grams of 
sodium hydroxide, the product hot filtered, and the dyestuff residue 
washed and dried. The resulting blue dye is slightly soluble in 
water and may correspond to Celatene Blue. Also see British 
Patent No. 253,584. 

British Patent No. 233,813, February 27 and November 22, 
1924, to the British Dyestuffs Corporation, J. Baddiley, and H. 
Browning, Jr., given in connection with the vat dyes, covers the 
dyeing of acetate silk by means of aqueous suspensions of vat 
dyes, as well as certain indophenols. 

According to British Patent No. 234,533, January 26, 1924, to 
Scottish Dyes, J. Thomas, and L. J. Hooley, hydroxyanthraqui- 
none and their chloro derivatives suitable for dyeing acetate silk 
may be prepared by the condensation of phthalic anhydride with 
o-chlorophenol or its derivatives, such as 2, 4-dichlorophenol in 
sulfuric acid solution in the presence of boric acid. The hydroxy- 
anthraquinone derivatives are separated by the action of alkalies. 
For example, chloroquinizarin may be prepared by slowly adding 
20 parts of 2, 4-dichlorophenol to 65 parts of 20 per cent oleum 
while stirring and cooling to hold the temperature below 25° C. 
(77° F.). When a test sample’ of this is soluble in a 12 per cent 
sodium chloride solution, 22 parts of phthalic anhydride, 10 parts 
of boric acid and 30 parts of 20 per cent oleum are added, and 
the temperature raised to 180° C. in the course of about three 
hours. It is then raised to about 200° C. in an hour and held at 
195 to 200° C. for about 6 hours. The solution is then diluted 
with water and the precipitate extracted with dilute alkali, whereby 
an insoluble substance which appears to be 1, 4-dihydroxy-2- 
chloroanthraquinone is obtained as residue. The soluble portion 
dyes acetate silk a red shade and wool in reddish shades which 
become bluer on chroming. This may cover Celantene Red B. 

In another example, a mixture of 150 parts by weight of 94 
per cent sulfuric acid, 30 parts of phthalic anhydride, 16 parts of 
o-chlorophenol and 16 parts of boric acid, is heated to 180° C. for 


PREPARATION AND APPLICATION PATENTS 323 


3 hours, the temperature is raised to 200° C. for an hour and then 
maintained at 195 to 200° C. for 6 hours. After cooling, boiling 
with 3000 parts of water, and filtering, a quantity of the residual 
paste equivalent to 10 parts of dry material is boiled with 1000 
parts of water and 32 parts of ammonia. The insoluble portion is 
filtered off, and the soluble portion, consisting mainly of 2, 3- 
chlorohydroanthraquinone, is precipitated by acidification. The 
portion insoluble in ammonia gives fast orange-yellow shades on 
acetate silk. This may be either Celatene Yellow, Orange, or 
Golden Orange. 

Fast greenish-yellow shades on acetate silk, which are not pho- 
totropic, may be obtained by means of monoazo dyestuffs prepared 
by coupling 1, 3-dihydroxyquinoline with diazotized aniline or its 
homologues or derivatives, as described in British Patent No. 
11,205 of 1905. This process is covered by British Patent No. 
236,037, June 20, 1924, to Baddiley, Hill, and the British Dyestuffs 
Corporation. Possibly this patent may cover Dispersol Yellow 
3G, the exact composition of which is not commonly known at 
present. 

British Celanese Ltd., in British Patent No. 237,943, April 4, 
1924, states that unsulfonated nitro derivatives of diarylamines 
which may or may not contain hydroxyl, amino, or chloro groups, 
may be applied to acetate silk by the usual dispersol methods 
of dyeing, printing, or stencilling. They may be dissolved in a 
sulfonated fatty acid or carboxylic or phenol sulfuric acid, as in 
British Patent No. 219,349, to give greenish, golden-yellow, or- 
ange, and brown shades which are generally of very good fastness 
to light, soaping, acids, alkalies, and ironing. Suitable derivatives 
include 2, 4-dinitrodiphenylamine, 2, 4-dinitro-4-hydroxydiphenyl- 
amine (see British Patent No. 222,001), 4-chloro-4-nitrodiphenyl- 
amine, 4-chloro-2-nitro-4-aminodiphenylamine, 4, 4’-dinitro-2’-hy- 
droxydiphenylamine, 4-nitrophenyl-4’-nitro-2’-tolyulamine, and 2, 
4-dinitrophenyl-B-naphthylamine. Such compounds usually have 
no affinity for cotton. 

For instance, 100 pounds of acetate silk may be dyed a full 
gold shade as follows: Heat 5 pounds of a 20 per cent aqueous 
paste of 2, 4-dinitro-4-hydroxydiphenylamine with 7.5 pounds of 


324 ACETATE SILK 


65 per cent aqueous ammonium sulforicinoleate until the mass is 
homogeneous. Then dilute this with boiling water to make 12 
gallons and sieve it into a 200-gallon dye bath. The wet-out ace- 
tate silk is then entered and dyed at 65 to 75° C. (149 to 167° F.). 

Another patent covering the dispersol products is British Patent 
No. 238,936, May 26,'1924, to Scottish Dyes, E. G. Beckett, and 
J. Thomas. It states that acetate silk may be dyed colors which 
are fast to light by means of aqueous suspensions or colloidal solu- 
tions of derivatives (other than amino derivatives) of a-hydroxy- 
anthraquinone, which contain at least one other hydroxyl or halo- 
gen substituent in the molecule, but not those polyhydroxyanthra- 
quinones which contain two hydroxyl groups in the ortho position 
to one another. Suitable dyes are 1, 5-dihydroxyanthraquinone 
(yellow), 1-hydroxy-4-chloroanthraquinone (yellow), 1, 6-dihy- 
droxyanthraquinone (yellow), 1, 4-dihydroxyanthraquinone (or- 
ange), leuco-1, 4-dihydroxyanthraquinone (reddish-yellow), 1, 4, 
6-trihydroxyanthraquinone (reddish-yellow), and 1,4, 6-trihy- 
droxy-2-chloroanthraquinone (reddish-yellow). These dyes are 
suitable for use on the acetate silk of acetate silk-cotton unions, 
since they do not dye cotton. As an example, a lemon yellow color 
is obtained by working 100 parts of the yarn for an hour at 70° 
C. (158° F.) in a dye bath containing 10 parts of a 10 per cent 
paste of 1-hydroxy-4-chloroanthraquinone in suspension in 2000 
parts of water. The dyed fabric should be soaped lightly, rinsed, 
and dried, as usual. 

The British Celanese Company and G. H. Ellis obtained British 
Patent No. 239,470 on April 4, 1924, covering the dyeing, sten- 
cilling, or printing of acetate silk by means of aqueous suspensions 
or colloidal solutions, but not solubilized forms (as in British ate 
ent No. 219,349) of unsulfonated mono-, di-, or poly-nitro deriva- 
tives of diarylamines, but excluding 2, 4-dinitrodiarylamines (see 
British Patents No. 237,943 and No. 222,001), which may or may 
not contain hydroxy, chloro, amino, or other substituent groups. 
Such substances have practically no affinity for cotton, and only a 
slight affinity for silk and wool. These are either insoluble or only 
slightly soluble in water, dilute acids, or alkalies, and are applied 
in the form of fine suspensions, to which may be added protective 


PREPARATION AND APPLICATION PATENTS 3825 


colloids, such as glue, starch, or gums. They yield greenish-yellow 
to brown shades on acetate silk which generally show very good 
fastness to light, soaping, acid, alkalies, and ironing. Suitable com- 
pounds include 4-nitrodiphenylamine, 4-nitrophenyl-4’-tolylamine, 
4-chloro-2-nitrodiphenylamine, 4-nitro-4’-chlorodiphenylamine, 4- 
chloro-2-nitro-4’-methoxydiphenylamine, 4-chloro-2-nitro-4’-hy- 
droxydiphenylamine, 4-chloro-2-nitro-3’-aminodiphenylamine, 4,4’- 
dinitrodiphenylamine, 4, 4’-dinitro-3’-hydroxydiphenylamine, 4-ni- 
trophenyl-4’-nitro-2’-tolyamine, 2, 4-dinitrodiphenylamine, 4, 4’-di- 
chloro-2-nitrodiphenylamine, and 4, 4’-dinitro-2’-hydroxydiphenyl- 
amine. | 

British Patent No. 242,393, September 19, 1924, an addition to 
patent No. 219,349, to British Celanese and Ellis covers another 
dispersing agent for the dispersol dyes mentioned in the original 
patent, as well as in patents No. 224,681, No. 227,183, and No. 
237,943. According to this patent, solubilized dyestuffs suitable 
for dyeing acetate silk are prepared by treating the insoluble dyes 
with sulfoaromatic fatty acids; as, for instance, sulfobenzene- 
stearic acid (Twitchell reagent), or their derivatives, such as sul- 
fophenolstearic acid and sulfonaphthalenestearic acid, or their 
salts, which act as solubilizing agents. A suitable solubilizing 
agent is prepared by adding a cold paste containing 25 kilograms 
of naphthalene or benzene and 25 kilograms of oleic acid to 100 
kilograms of 20 per cent oleum at 40° C. (104° F.), the tempera- 
ture being then raised to 100° C. (212° F.) and maintained for 3 
hours. The product is poured into 250 liters of water containing 
50 kilograms of sodium chloride and the upper layer separated and 
purified. Also see United States Patent No. 1,610,961. 

According to British Patent No. 242,711, August 14, 1924, to 
British Celanese, G. H. Ellis, and W. O. Goldthorpe, the dyeing, 
printing, or stencilling of acetate silk with insoluble dyes and fatty ° 
substances, such as sodium sulforicinoleate, as described in British 
Patent No. 219,349, No. 224,681, No. 227,183 and No. 237,943, 
is aided by the presence of secondary solvents. These secondary 
solvents may be alkyl or alkylene halides, such as tetrachlorethane 
and trichlorethylene ; simple or mixed cyclic or aromatic deriva- 
tives containing one or more amino, chloro, or hydroxy groups, 


326 ACETATE: SICK 


such as cresols, alkylanilines, toluidines, chlorophenols, and mono- 
or poly-chlorobenzenes ; and hydrogenated derivatives of such or 
other aromatic compounds; as for instance hexahydrophenol, 
hexahydrocresols, hexahydrobenzene, decahydronaphthalene and 
tetrahydronaphthalene. The presence of such solvents results in 
improved depth of shade, penetration and levelness, and a conse- 
quent economy in dyes. The mixture of dye, oil, and solvent may 
be made in any order, much or little water may be used, and the 
mixture may be subsequently concentrated or dried before addition 
to the dye bath or printing paste. Insoluble diazotizable substances 
may be applied in this way for development on the fiber. 

British Patent No. 243,505, July 2, 1924, to J. Thomas and the 
Scottish Dyes, Ltd., covers the preparation of certain aminoanthra- 
quinone compounds. Nitroanthraquinone derivatives substituted 
in the B-position are produced by condensing benzoylbenzoic acids 
substituted in the p-position in the presence of strong sulfuric acid 
or weak oleum, and nitrating the anthraquinone derivatives formed 
by the condensation, without separating them from the solution. 
The products are subsequently converted into the corresponding 
amino-compounds and simultaneously purified by treatment with 
alkaline reducing agents followed by washing with water. For 
example, a solution of 11.1 parts by weight of p-chlorobenzoylben- 
zoic acid, which is prepared by condensing chlorobenzene with 
phthalic anhydride in the presence of aluminum chloride, in 55.5 
parts of 6 per cent oleum, is maintained at 140° C. for 2 hours, 
and then cooled below 18° C., when 3.5 parts of sodium nitrate 
are added during a half-hour, while stirring. After keeping for 
16 hours, the melt is boiled with 600 parts of water, and filtered 
after further dilution with water. A quantity of the moist product 
containing 10 parts of crude nitro-2-chloroanthraquinone is boiled | 
for an hour with a solution of 25 parts crystalline sodium sulfide in 
450 parts of water, and the product is filtered off and washed, 
yielding 9 parts of amino-2-chloroanthraquinone, melting at 176 
to 180° C. Nitro and amino-2-methylanthraquinone are prepared 
in the same manner from p-toluoylbenzoic acid. Also see British 
Patents No. 228,634, No. 230,130, No. 231,206, No. 238,590 and 
No. 238,936. 


PREFARATION AND APPLICATION PATENTS 327 


British Patent No. 244,143 to the British Celanese Company, 
G. H. Ellis, and E. Greenhalgh, covers the printing or stencilling 
of acetate silk by means of insoluble or relatively insoluble color- 
ing matters, compounds, or components; for example, those re- 
ferred to in patents No. 219,349, No. 224,681, No. 224,925, No. 
227,183 and No. 237,943, solubilized by treatment with the solubil- 
izing agents of patents No. 219,349 and No. 224,925. In this 
patent it 1s proposed to add one or more swelling agents having a 
solvent action towards cellulose acetate to the printing paste. The 
thiocyanates of alkali metals or of ammonia (particularly for 
neutral or alkaline preparations), zinc chloride or nitrate, and salts 
of organic sulfonic acids such as those of benzene, naphthalene, or 
anthracene, or of their substitution derivatives, for example, 
naphthol, phenol, or aminonaphthols, are mentioned as suitable 
products. In an example, a bluish-red shade is obtained on acetate 
silk by printing on a color paste containing 40 grams of paste pre- 
pared from 2, 4-dinitrobenzene-1-azodimethylaniline solubilized by 
pretreatment with sodium sulforicinoleate, 5 grams of soda ash, 20 
grams of ammonium thiocyanate, 40 grams of water and 295 
grams of a thickening agent, prepared from British gum and gum 
arabic. Also see the patents covering the ‘assistants’ used for 
the basic dyes, the ammonium thiocyanate method of applying 
basic dyes, and Dyeing by Precipitation, Chapters X and Xi. 

British Patent No. 244,936, January 24, 1925, to L. B. Holliday 
and Company, and A. Young, states that acetate silk may be dyed 
by aqueous solutions or suspensions of the products obtained by 
condensing 1-chloro-2, 4-dinitrobenzene-6-sulfonic acid or 1-chlo- 
ro-2, 6-dinitrobenzene-4-sulfonic acid or their salts with aromatic 
substances containing one or more amino- or one or more hydroxy 
groups, as for instance aniline. For example, 320 grams of potas- 
sium 1-chloro-2, 4-dinitrobenzene-6-sulfonate are boiled with 100 
grams of sodium acetate in a liter of water. Ninety-three grams 
of aniline are then added to the boiling solution, when a bright 
yellow solid separates almost immediately. When the reaction is 
complete, the liquor is cooled and the 2,4-dinitrodiphenylamine-6- 
sulfonic acid collected. The dyeing may be carried out by the im- 
mersion of the acetate silk in an aqueous solution or suspension 


328 ACETATE SILK 


of the dyestuff and heating to about %5° C. A little ammonia, 
Turkey-red oil, or soap may be added and the goods are finally 
soaped, rinsed, and dried. 

British Patent No. 246,984, January 7, 1925, an addition to 
patent No. 224,077, to the British Dyestuffs Corporation, J. Bad- 
diley, A. Shepherdson, H. Swann, J. Hill, and L. G. Lawrie, is an 
improvement over the original patent, in that it is proposed to use 
much less dispersing agent in the preparation of the dispersol dye 
product. For instance, less than 10 per cent, on the weight of 
dry dyestuff, of the condensation products of napthalene with 
formaldehyde is used in solubilizing the dye. As an example, a 
dye paste consists of 10 parts of aminoanthraquinone, 0.25 part of 
the dispersing agent, and 89.75 parts of water. Further, complete 
neutralization of the acidic dispersing agent in the solubilized dye- 
stuff paste by the addition of ammonia is preferred to the partial 
neutralization with sodium hydroxide as mentioned in the chief 
patent. 

British Patent No. 251,155, August 14, 1925, to Johnson for the 
Badische Company and French Patent No. 600,106, June 26, 1925, 
to the same company cover the dyeing of acetate silk in fast shades 
from aqueous solutions or suspensions, with or without dispersing ~ 
agents, such as Turkey-red oil, of azo dyes containing one or more 
monohydroxyethylamino groups (-NH.CH2.CH2.OH) but no sul- 
fonic acid groups. A suitable dye is obtained by coupling diazo- 
tized p-nitroaniline or m-nitro-p-toluidine with hydroxyethylani- 
line in acetic acid solution. 

British Patent No. 253,584, March 16, 1925, to Scottish Dyes, 
Thomas, Beckett, and Tonkin, an addition to Patent No. 231,206, 
specifies that an alkaline earth sulfide, such as calcium hydrogen 
sulfide, may be used to advantage in place of the alkali sulfide of 
the original patent. Thus, in place of 168 parts of sodium sulfide 
crystals, 73 parts of calcium hydrogen sulfide may be used. 

According to British Patent No. 253,978, March 18, 1925, to 
G. H. Ellis and the British Celanese Company, acetate silk may 
be dyed, printed or stencilled with dyestuffs of the stilbene group 
containing no sulfonic groups, either by the dispersol process, as 
in Patent No. 224,925, or they may be formed within the acetate 


PREPARATION AND APPLICATION PATENTS 329 


silk fiber by coupling the diazotized aminostilbenes with suitable 
developers. The following are mentioned as suitable dyestuffs: 
stilbenedisazobisphenol (yellow), | stilbenedisazo-m-toluidine 
(gold), stilbenedisazo-a-naphthylamine (red), aminostilbeneazo-m- 
phenylenediamine (gold), and aminostilbeneazo-m-toluidine (yel- 
low). Diaminostilbene may be applied to acetate silk and then 
diazotized and coupled with phenol (gold), 1-phenyl-3-methyl-5- 
pyrazolone (red), diethylaniline (red), m-phenylenediamine (red- 
dish-brown), m-phenylenediamine (reddish-brown) ; a-naphthyla- 
mine (plum), B-naphthylamine (plum), or B-hydroxynaphthoic 
acid (black). These dyestuffs have little or no affinity for fibers 
other than acetate silk. 

Also see British Patent No. 255,962 in Chapter XVI. 

British Patent No. 256,205 to the Society of Chemical Industry 
of Basle covers the preparation of monoazo dyestuffs which give 
a fast yellow color on acetate silk by coupling 1-(2’-chlor ) -pheny]l- 
3-methyl-5-pyrazolone with unsulfonated diazo compounds, such 
as diazotized aniline. For use in dyeing acetate silk the dyestuff 
is ground in the form of its moist press cake with a protective col- 
loid, for instance sulfite cellulose liquor. 

British Patent No. 256,281 to R. F. Thomas, J. Thomas, and 
Scottish Dyes, covers the nitration of bz.-halogenated benzan- 
thrones with concentrated nitric acid in nitrobenzene solution. The 
nitro compound is reduced with zinc dust and concentrated hydro- 
chloric or sulfuric acid in aniline or pyridine solution. The amino 
compound formed has a slight affinity for acetate silk and can be 
used as an intermediate product for other dyes. Halogenated 
alkyloxybenzanthrones are obtained by replacing the amino group 
by a hydroxyl group, and then alkylating with an alkyl sulfate in 
the presence of nitrobenzene. Fusion with alcoholic potash yields 
products, probably alkyloxyisodibenzanthrones, which dye cotton, 
from a violet-blue vat, a reddish-blue color of excellent fastness 
to light, washing, and bleaching. 

British Patent No. 257,353, June 4, 1925, to the British Dye- 
stuffs Corporation, W. H. Perkin and C. Hollins, states that sub- 
stances which are probably anthraquinonyliminoanthrones are ob- 
tained by the condensation of an anthraquinone derivative contain- 


330 ACETATE SILK 


ing a primary amino group with aminoanthraquinone, diaminoan- 
thraquinones or their simple derivatives, such as diaminoanthraru- 
fin and diaminochrysazin, in the presence of anhydrous calcium 
chloride or iodine as condensing agent at 200 to 300° C. The re- 
sulting products are not vat dyestuffs, but have a good affinity for 
acetate silk when applied direct from suspension in water, with or 
without the addition of dispersing agents. 

Under the conditions mentioned 2 molecules of a-aminoan- 
thraquinone give a deep reddish-orange dyestuff. One molecule 
of a-amino- and 1 molecule of 1, 4-diaminoanthraquinone a crim- 
son direct, or a brownish-orange from a vat; a-amino- and 1, 5- 
diaminoanthraquinone a brownish-orange. a-Amino- and 1,8-di- 
aminoanthraquinone a brick-red ; a-aminoanthraquinone and diami- 
noanthrarufin give a bright golden-brown. B-Aminoanthrarufin 
and diaminochrysazin give a drab. Equimolecular proportions of 
the compounds are finely ground with an equal weight of dry cal- 
cium chloride, and the mixture is heated at 200 or 250°C. for 13 
to 3 hours. The small sublimate of aminoanthraquinone is re- 
moved and the bulk boiled with water to remove calcium chloride. 
The insoluble residue may be used directly, or after purification 
by dissolving in hot acetic acid and again precipitating with water. 

British Patent No. 258,960, July 4, 1925, to the British Alizar- 
ine Company and C. M. Barnard covers the condensation of amino- 
anthraquinones and -benzanthrones with citric acid. For example, 
20 grams of 1,4-diaminoanthraquinone are boiled with 80 grams of 
crystallized citric acid under a reflux for an hour, without a diluent. 
The condenser is then removed and the heating continued at 150° 
C. until a sample is completely soluble in sodium carbonate solu- 
tion. The melt is then poured into 500 cubic centimeters of hot 
water, boiled, cooled, and filtered. The solid is dissolved in sodium 
carbonate solution or aqueous ammonia and the dye salted out or 
the solution evaporated to crystallization. The product dyes ace- 
tate silk a magenta color. 

German Patent No. 303,121, August 8, 1916, to S. Aschkenasi 
‘s of interest in that it appears to antedate the use of some of 
these dispersing agents in connection with dyeing. Probably the 
method covered by this patent could be used in the preparation of 


PREPARATION AND APPLICATION PATENTS 331 


dispersol baths of vat or other insoluble dyes for use on acetate 
silk. This patent states that pastes of insoluble dyestuffs may be 
prepared by the addition of so-called “fat splitting” agents, such 
as l'witchell reagent, hydroricinoleic acid, naphthalene sulfonic 
acid splitter, etc. Indigo pastes may be prepared by adding one 
to three per cent of the fat splitter, on the weight of the dye, and 
stirring with water. The preparation of dye pastes with Turkon 
oil and other fatty derivatives is discussed, but it is claimed that 
at least fourteen times as much Turkon oil is required to give the 
same emulsifying action as the fat splitters, therefore the latter are 
more suitable for concentrated pastes. 

The splitters may also be used as an addition to the dye bath to 
produce emulsification and thus allow the use of neutral or acid 
hydrosulfite vats. In this method, the splitter is added to the or- 
dinary alkaline vat, after reduction by hydrosulfite at a tempera- 
ture of not over 40° C. (104° F.). In the case of Indigo, the ad- 
dition of 1 to 3 per cent of Twitchell reagent, on the weight of 
Indigo, is recommended. Thioindigo Scarlet is also mentioned as 
particularly suited for application by this method. 

Clavel in United States Patent No. 1,517,709, December 2, 1924, 
covers the application of dyes in suspension to acetate silk and 
cotton or other acetate silk unions. In this process the cotton 
may be dyed to shade in the usual manner by a sulfonated dye 
which has no affinity for acetate silk. After rinsing, the acetate 
silk is dyed in a bath containing an insoluble dye such as Induline 
in suspension, in the presence of acetic acid at about 60 to 72° C. 
(140 to 160° F.). The dyed fabric is given a final treatment at 
32° C. (90° F.) in a bath containing acetic or formic acid and an 
emulsion containing olive oil and olive-oil soap. The dyeing pro- 
cess may be reversed if desired, so as to dye the acetate silk first. 

The preparation of the compounds mentioned in British Patent 
No. 214,765 is covered by United States Patent No. 1,528,470, 
March 8, 1925, to H. A. E. Drescher and J. Thomas. Halogen 
derivatives of anthraquinone are treated with an imide of a di- 
basic acid, such as phthalimide, in the presence of copper and an 
acid absorber, such as sodium acetate, at approximately 180 to 
200° C. in order to eliminate the halogen in the form of an acid 


332 ACETATE SILK 


and form another derivative from the anthraquinone and the imide. 
This product can be treated with an acid, such as sulfuric acid, to 
regenerate the dibasic acid and an amino derivative of anthraqui- 
none formed. Numerous examples are given, including the prepa- 
ration of 1-phthalimidoanthraquinone from 1-chloroanthraquinone 
and its conversion into 1-aminoanthraquinone ; production of 1, 
5-diphthalimidoanthraquinone and its conversion into, 1, 5-diam- 
inoanthraquinone ; 1-chloro-5-phthalimidoanthraquinone from 1, 
5-dichloroanthraquinone and its conversion into 1-chloro-5-amino- 
anthraquinone ; 1-phthalimido-2-nitroanthraquinone from 1-chloro- 
2-nitroanthraquinone and its conversion into 1-amino-2-nitroan- 
thraquinone ; 1-amino-2-methyl-4-phthalimidoanthraquinone from 
1-amino-2-methyl-4-bromoanthraquinone and its conversion into 
diamino-2-methylanthraquinone ; 1-methylamino-4-phthalimidoan- 
thraquinone from 1-methylamino-4-bromoanthraquinone and its 
conversion into 1-methylamino-4-aminoanthraquinone ; 1-phthali- 
mido-2-aminoanthraquinone from 1-chloro-2-aminoanthraquinone 
and its conversion into 1,2-diamoanthraquinone ; 2-phthalimidoan- 
thraquinone from 2-bromoanthraquinone and its conversion into 
2-aminoanthraquinone ; and 1-succinimidoanthraquinone from 1- 
chloroanthraquinone. . . 

United States Patent No. 1,532,921, April 7, 1925, to F, Munz, 
utilizes ordinary soaps, sulfonated products, Turkey-red oils, 
monosolvol, etc., as well as organic solvents, such as benzene and its 
homologues, hydrated carbohydrates, chlorocarbohydrates and sim- 
ilar substances, as solvents for the insoluble products to be applied 
by the dispersol method. He states that alkalies, such as soda ash 
and ammonia, frequently assist in solubilizing the dyes. For exam- 
ple, acetate silk may be dyed a yellow shade with 2 per cent, on the 
weight of the fabric, of dimethylamidoazobenzene, 4 per cent of 
Turkey-red oil, 4 per cent of solvent naphtha and 0.4 per cent of 
soda. These are boiled with 40 to 50 times their weight of water 
and added to the dye bath at 80 to 85° C. (176 to 185° Bi, he 
acetate silk is dyed for about three-quarters of an hour to ex- 
haust the bath, rinsed and finished in a dilute acetic acid bath. 

In the same manner, a deep black may be obtained on acetate 
silk with 3 per cent of the dyestuff derived from o-anisidine-a- 


PREPARATION AND APPLICATION PATENTS 333 


naphthylamine, 8 per cent of common curd soap, 5 per cent of 
tetralin and 1.5 per cent of soda ash. This is handled in the same 
manner as the above but at 60 to 65° C. (140 to 149° F.), then 
diazotized and developed with B-hydroxynaphthoic acid. 

A clear blue color on acetate silk may be obtained in the same 
manner but using 0.5 per cent of dianisidine, 2 per cent of soap, 
1.5 per cent of tetralin and 0.5 per cent of soda ash. This is diazo- 
tized and developed with B-hydroxynaphthoic acid also, as 
above. 

United States Patent No. 1,610,961 to R. Metzger, assigned to 
the Interessen Gemeinschaft, covers the application of insoluble or 
difficultly soluble dyestuffs, bases, amino compounds, naphthols. 
etc., to acetate silk by the dispersol process, using the catalytic 
organic fat saponifiers as the dispersing medium. Suitable com- 
pounds are, Twitchell’s reagent, naphthenic acids, mixed fatty 
acid and naphthalenesulfonic acids, and also the alkylated naphtha- 
lenesulfonic acids such as isopropylated napththalene, or butylated 
or isobutylated naphthalenesulfonic acids, or the salts thereof. 

For application, the dyestuff or other compound to be applied to 
the acetate.silk is dissolved or dispersed in the above suitable re- 
agent to form the usual concentrated solution which is added to 
the dye bath; or the dye bath may be prepared directly with the 
dyestuff while adding the dispersing agent. 

For example, 100 parts of acetate silk may be dyed a strongly 
fluorescent yellow by 2 parts of 3-aminobenzanthrone dissolved 
or dispersed in a suitable amount of Twitchell’s reagent. This 
is added to 2000 to 3000 parts of water containing a little soap 
and the goods entered at 60 to 70° C. In the same manner a red 
color may be obtained with 1 per cent of benzoyl-1-aminobenzan- 
throne. 

One per cent of 5-nitro-1,4-diaminoanthraquinone, on the weight 
of acetate silk, gives a violet color when dissolved in concentrated 
aqueous solution of sodium diisopropylnaphthalenesulfonate and 
added to a dye bath containing 20 grams per liter of concentrated 
neutral sulfite waste liquor. | 

1-Amino-4-anilidoanthraquinone dissolved in butylated naph- 
thalenesulfonic acid, obtained by condensing normal butanol with 


334 ACETATE SILK 


naphthalenesulfonic acid, gives a bright blue color. About 10 
grams of the sulfonic acid, per liter of dye bath, should be used. 
a-Naphthylamine (diazotized) with m-phenylenediamine, a-amino- 
a-naphthoquinone, 8-nitro-2-aminonaphthalene, Methyl Violet 
base, a-naphthylamine (diazotized) with p-hydroxybenzoic acid, 
are also mentioned. Also see German Patent No. 303,121, and 
British Patents No. 224,925, and No. 242,393. 


Dispersol Dyes on Other Fibers 


While the dispersol type of dyes were developed especially for 
use on acetate silk, at least some of them are applicable to other 
Gbers. In the discussion of the Celantene patents, it was men- 
tioned that certain of the products are applicable to cellulose fibers 
other than cotton. The following patents cover the application 
of dyes of this class to straw, jute, hemp, esparto, rafha, flax, 
ramie, wool, true silk, “resisted” or “immunized” cotton, etc. 

According to British Patent No. 228,634, November 8, 1928, 
to J. S. Wilson, J. Thomas, and Scottish Dyes, wool is dyed by 
immersion in aqueous suspensions of mono-, di- or triaminoan- 
thraquinones, alkylaminoanthraquinones, or substituted derivatives 
of these substances, but excluding hydroxyl derivatives or related 
acid dyestuffs. Dispersing agents such as alcohol and cresol are 
used. For example, one hundred pounds of thoroughly wet-out 
woolen yarn may be dyed in a 200 to 400 gallon (British) dye bath 
containing 2 to 4 pounds of alcohol and 1 pound of 1-amino-2- 
methylanthraquinone at 90° C. (194° F.) for a half to three- 
quarters of an hour. The dyed yarn should be rinsed to remove 
undissolved dyestuff and dried. Suitable dyestuffs are 1-methyl- 
aminoanthraquinone, 2-aminoanthraquinone, 1-chloro-2-aminoan- 
thraquinone, 1, 4-diaminoanthraquinone, 1-methylamino-4-amino- 
anthraquinone and 1-methylamino-4-amino-2-bromoanthraquinone. 

British Patent No. 230,130, October 29, 1923, to J. S. Wilson, 
J. Thomas, and Scottish Dyes states that true silk may be dyed 
by immersion in an aqueous suspension of monoamino-, diamino-, 
triamino-, Or alkylaminoanthraquinones and their derivatives, but 
excluding sulfonated or carboxylated derivaties, which are usually 


PREPARATION AND APPLICATION PATENTS 335 


regarded as true silk dyestuffs. Suitable products are 1-methyl- 
amino-, 1-amino-2-methyl-, 2-amino-, 1,4-diamino-, 1-methyl- 
amino-4-amino-, and triamino-anthraquinone. For example, 5 
parts of true silk may be dyed a bluish-red color by immersion at 
80 to 90° C. (176 to 194° F.) for 45 minutes in 100 parts of 
water containing 0.5 part of a 10 per cent paste of 1-methylamino- 
anthraquinone. After dyeing the fabric should be rinsed and 
lightly soaped in the usual manner. These dyes are also applicable 
to unions containing true silk. 

British Patent No. 238,590, April 24, 1924, to R. F. Thompson, 
J. Thomas, and Scottish Dyes, covers the application of similar 
anthraquinone derivatives to cellulose and ligno-cellulose fibers, 
such as straw, jute, hemp, esparto, raffia, flax and ramie, but not 
cotton. These fibers are dyed fast shades by immersion in hot 
alkaline or acid liquors containing suitable aminoanthraquinones or 
their derivatives in suspension or in solution. For instance, 
straw is dyed an orange shade of good fastness to light by treat- 
ing it for an hour in a boiling alkaline dye bath consisting of 100 
gallons of water, 2 pounds of soda ash, and 5 pounds of a 10 per 
cent paste of 1l-amino-2-methylanthraquinone. Thirty to forty 
pounds of jute, hemp, straw or tagel may be dyed a reddish-violet 
shade of excellent fastness to light by boiling for an hour in a dye 
bath containing 100 gallons of water, 30 pounds of acetic acid and 
10 pounds of a 10 per cent paste of 1,4-diaminoanthraquinone. 
Suitable dyestuffs include 1-chloro-2-aminoanthraquinone (yel- 
low), 1-methylaminoanthraquinone, and the nitration product of 
hexa-aminodianthraquinonylthio-ether (blue). 

According to British Patent No. 246,609, November 17, 1924, to 
A. E. Woodhead and the Sandoz Chemical Company, immunized 
or resisted cotton (see British Patents No. 195,619, No. 233,704, 
No. 241,854 and German Patent No. 346,883), prepared by treat- 
ing ordinary cotton with alcoholic sodium hydroxide and p-tolu- 
enesulfochloride, may be dyed by means of insoluble or difficulty 
soluble dyestuffs which have been solubilized by pretreatment 
with suitable dispersing agents, such as the higher fatty acids or 
their sulfo-derivatives, their alkali-metal or ammonium salts. The 
methods of dyeing are similar to those generally used for acetate 


336 ACETATE SILK 


silk except that the temperature of the bath is preferably 75 to 
95° C. (167 to 208° F.). | 

This patent covers the use of the following dyestuffs in this 
manner: azo dyestuffs prepared from nitroanilines, dinitroani- 
lines, nitrotoluenes, nitroxylidenes, anisidines, chloroanisidines, ni- 
troanisidines, phenetidines, chlorophenetidines, nitrophenetidines, 
or chloronitroanilines diazotized and coupled with aniline, methyl- 
aniline, dimethylaniline, ethyl- or diethylaniline, meéthylethylaniline, 
diphenylamine, methyl- or ethyl-diphenylamine, m-toluidine or 
p-xylidine. Aniline, chloroanilines, dinitroanilines, toluidines, 
xylidines, nitrotoluidines, nitroxylidines, anisidines, chloro- or ni- 
tro-phenetidines diazotized and coupled with a- or B-naphthyla- 
mine or their methyl, dimethyl, ethyl, diethyl, methylphenyl, or 
ethylphenyl derivatives. a- or B-naphthylamines, or their chloro- 
or nitro-derivatives diazotized and coupled with aniline or their 
alkyl- or aryl-aniline or naphthylamine derivatives mentioned 
above, or a- or B-naphthylamine. Naphthols, resorcinol, B-hydro- 
xynaphthoic acid and its anilide, toluidide, and similar derivatives 
coupled with diazotized amino bases such as m-nitroaniline and a- 
naphthylamine. This method of dyeing allows the production of 
two-color effects in union fabrics containing ordinary cotton and 
other fibers, together with immunized cotton. 

Apparently, if not too expensive, this new process of resisting 
or immunizing cotton to the direct cotton dyes offers a new method 
of obtaining two color effects, very probably in one dye bath. If 
the extent of the change (immunizing) process may be varied 
within wide limits, probably it will be possible to obtain a variety 
of products each one of which may dye in more or less different 
depths of shade in the one dye bath. In fact this very multiplicity 
of possible products may be a detriment to the whole process, un- 
less it is possible to so control the process as always to get the 
same dyeing properties in the “immunized” product. Undoubtedly 
this treated fiber will be dyed, more or less, by many acetate silk 
dyes of the dispersol class, but the shade of the immunized cotton 
and acetate silk, from the same dye bath, will probably be quite 
different. It undoubtedly offers another method of obtaining a 
variety of color effects in textiles. 


CHAPIER XXIV 


COLOR PRINTS AND DISCHARGES ON ACETATE 
SILK AND ACETATE SILK UNIONS 


THE printing properties of the various groups of dyes which 
are applicable to acetate silk have been briefly mentioned in con- 
nection with the discussion of each class of dyestuffs. Davies, 
who is quite an authority on this subject, says that to a certain 
degree the printing of acetate silk offers but little difficulty, but 
that this can be regarded as true only if we are considering the 
direct printing of an all-acetate-silk piece of goods. The state- 
ment has frequently appeared in the literature that the printing 
of acetate silk is even simpler than the dyeing and quite a variety 
of processes are used. 

In applying the basic, certain acid, mordant, vat, and many 
other special dyes which have an affinity for acetate silk, formulas 
similar to those used for the application of these dyes to other 
fibers will frequently serve without much change. Glucose, Brit- 
ish gum, and tragacanth have been recommended as thickening 
agents for acetate silk printing pastes. Even the direct cotton 
dyes, which have no affinity for acetate silk, can be printed on this 
fiber with an alkaline thickener and steamed to produce prints of 
ordinary direct color fastness. In this case the direct color is 
fixed solely by the local or surface saponification of the printed 
portions of the acetate silk, due to the alkalinity of the paste.* 


* The direct color printing paste may be prepared as follows :° 
2 grams of direct dyestuff dissolved in 
40 cubic centimeters of water and 
1 gram of sodium phosphate. 
This mixture is added to 80 cubic centimeters of 60 per cent gum arabic 
thickening, and finally 20 cubic centimeters of 76° Tw. sodium hydroxide 
solution are added. The goods are printed, aged at 101° C. (214° F.) for 30 
minutes with dry steam, and washed off. 
In steaming acetate silk materials, care must be taken to insure the use of 
only dry steam, otherwise the moisture present may blind the fiber. 
Schneevoigt® prints acetate silk with alkaline pastes of the vat dyes and 
states that the local saponification of the fiber occurs without a serious loss 
of luster. He also mentions a superficial saponification before the. printing. 
The basic dyes are equally fast on this superficially saponified acetate silk 
and cotton. 


337 


338 ACE VATE Sligk 


In fact many color pastes for acetate silk printing contain 
sodium hydroxide, the prints being fixed by steaming. This 
of course causes a local saponification of the acetate silk fiber, 
which in most cases is not objectionable in the case of small 
printed designs, as there is very little alteration in appearance or 
loss of weight, and it allows the use of a much wider range of 
dyestuffs. These alkaline pastes may also be used for printing 
acetate silk-cotton unions, covering both fibers in the one operation. 

Cotton? mentions that in Europe they are dyeing cotton-acetate 
silk combinations with direct cotton dyes, which of course leaves 
the acetate white, and then printing on a basic color discharge. 
This gives a very beautiful shot effect. The same kind of effects 
are also obtainable on acetate sill-viscose unions, or combinations 
with the other rayons. 

In printing the basic dyes on acetate silk, as well as other dyes 
which have an affinity for this fiber, and where alkaline pastes are 
not used, acetic acid (10%) is frequently added to the printing 
paste.> This acts as a solvent or swelling agent on the fiber, which 
serves to fix the color. The prints may be steamed without pres- 
sure, and washed. The basic dye prints may be fixed with tannin 
in the ordinary way. Also see British Patents No. 242,711, and 
No. 244,143, of Chapter XXIII, which refer to the use of special 
compounds in printing acetate silk. 

According to J. Pokorny® resorcinol may be useful in certain 
printing operations on acetate silk. He states that resorcinol is 
a solvent for basic dyestuffs and their lakes formed with tannic 
acid and various inorganic salts. Pastes prepared in this manner, 
when printed on fabrics containing acetate silk, usually partially 
deacetylate the acetate silk and generally give deep shades. 1{=1s 
possible that some of the Gallopont dyes recently developed by the 
Du Pont Company may be applicable in this manner, as they are 
probably compounds of basic dyes with suitable mordants, in a 
special solvent (not resorcinol). 

In connection with the use of solvents in printing acetate silk 
and unions containing this fiber, the British Patent No. 223,888 
to J. R. Geigy Company may be of interest. This patent covers 
the use of ethyleneglycol and ethylenechlorhydrin as solvents for 


EgLOR PRINTS AND DISCHARGES 339 


use in printing pastes, in place of gylcerol, acetin, phenol, aniline, 
alcohol, ethylenethiodiglycol, etc. At least some of the compounds 
mentioned are suitable for use alone or in combinations with 
other compounds either as solvents or swelling agents for acetate 
silk. By suitably combining these in a properly prepared printing 
paste, undoubtedly some very interesting effects could be obtained 
on acetate silk unions. Geigy claims that ethyleneglycol and 
ethylenechlorhydrin have a high solvent action towards many 
dyestuffs and aid the penetration of the printing pastes very 
materially. 

The printing of chrome dyes on acetate silk-cotton unions is not 
generally very satisfactory, as the long steaming necessary to fix 
the dyestuff usually destroys the luster of the acetate silk. Those 
which are fixed by only a short steaming may be applied in the 
regular way. 

Ellis* states that the three best types of dyes for the direct 
printing of Celanese are the basic, S.R.A., and Indigoid dye- 
stuffs. All of these are fixed very well without hydrolysis of the 
fiber, the S.R.A. and Indigoid dyes directly, by a simple steam- 
ing or ageing. Another method of printing the vat and sulfur dyes 
on acetate silk is by means of Sulfoxite C or Rongalite C, accord- 
ing to the following formula.t 

Method No. 82: Color Printing Paste for Sulfur or Vat Dyes 
on Acetate Silk. 

10 grams vat dye paste, 
2.5 to 5 grams sulfoxite C. 
3 cubic centimeters glycerol. 
25 cubic centimeters 76° Tw. sodium hydroxide solution, and 
75 cubic centimeters of British gum paste, 6 lbs. per gal. 

Print and age for 5 minutes at 101° C. (214° F.). Where the 
oxidation has not been complete, an after-treatment with dilute 
hypochlorite solution, as in Method No. 15 or No. 16. but more 
dilute, may be given. Rinse well and soap at about 82° C. (180° 
ea)? 

"Another formula® for vat dye printing paste is: 


10 to 15% of vat dye paste, 
3% glycerol, 


340 ACETATE SILK 


British Patent No. 256,238 to the Soc. Anon. des Etablissements 
Petitdidier, St. Denis, France, covers the printing of fabrics con- 
taining acetate silk and cotton or viscose. (1) The fabric is printed 
in the usual manner with a dyestuff such as one having an anthra- 
quinone base, certain acid dyestuffs such as Citronine, or a basic 
dyestuff mordanted with Acetanol. (2) The printed fabric is 
steamed to fix the dyestuff on the acetate silk. (3) The fabric is 
rinsed, whereby a portion of the coloring matter is removed from 
the cotton or viscose. (4) The fabric is optionally steeped in a 
dilute solution of hydrosulfite in order to remove all color from 
the cotton or viscose silk. The fabric may be finally dyed with a 
dyestuff which has an affinity for the cotton without appreciably 
staining the acetate silk. | 

Ellis‘ states that the “Rapid Fast’’® colors may also be printed 
on acetate silk, and suggests Diphenyl Black Base for black prints, 
with rather more oxidizing agent than is used for the same pur- 
pose on cotton. The usual chlorate-prussiate method usually 
gives good results. Also see Methods No. 59 and No. 60. 


Tonamine Prints 


The Ionamines have been successfully printed on acetate silk 
by means of a thickened dye paste containing an organic acid. 
After printing, the material is dried, steamed for 5 minutes or 
longer without pressure, and washed. It may then be diazotized 
and developed if necessary. While the shades are usually very 
good, they do not always have the desired fastness to washing. 
Typical examples of suitable dyestuffs are:> Ionamine A, Iona- 
mine B, Ionamine MA, Ionamine GA, and Ionamine Red KA. 
Also see Chapter XX. 


(Footnote continued ) 
4% of 76° Tw. sodium hydroxide solution, 
5% sodium carbonate, 
5% potassium carbonate, 
2.5% solution salt, 
7 to 8% Formosul, and 

60 to 65% British gum thickening (3 Ibs. per gal.). 

Print, age, wash, and soap as in method No. 82. Sulfur dyes may be 
applied by a similar process and Thional Printing Black No. 2, Thional 
Brown GD, and Thionol Green B are mentioned as suitable. 

¢ See Chapter XVI. 


COLOR PRINTS AND DISCHARGES 341 


Developed Colors 


As a class the developed colors, such as are obtained with the 
Azonines, Azoniles, Silkons, Azoles, etc., are not satisfactory for 
printing purposes on acetate silk, as the white grounds usually be- 
come more or less stained during the development.® 


Dispersol Prints 


The dispersol dyes (S. R. A.’s, Duranols, Celatenes, Celanthrenes, 
and Dispersols) may be effectively printed on acetate silk materials 
by simply thickening the dye paste, with or without a little am- 
monium thiocyanate, printing and steaming without pressure for 
10 to 30 minutes, with only minor variations from the usual print- 
ing practice. The addition of about a half pound of soluble oil to 
each hundred pounds of printing paste generally improves the 
shade. The S. R. A. dyes on Celanese are often extremely fast to 
soaping. Possibly the reducing substances, such as stannous chlo- 
ride or hydrosulfite are best suited for resisting the dispersol dyes, 
but this type of dye is not particularly adapted for resist work.‘ 


Printing Unions 

In printing acetate silk-cotton unions, pleasing two-color effects 
may frequently be obtained by applying suitable CR direct cotton 
dyes and dispersol dyes mixed in the one printing paste as in 
Method No. 83. In this manner each of the dyes colors its par- 
ticular fiber only, and the unfixed dye is later rinsed from the 
fabric. / 

Method No. 83: Two-Color Acetate Silk-Cotton Union Print- 
ing Paste. 


2 grams CR dyestuff dissolved in 
10 grams glycerol, 

23 grams hot water, and 

60 grams British gum thickener. 


* Satisfactory prints on acetate silk have been obtained with a printing 
paste containing 50 grams of a suitable anthraquinone dye, such as Yellow 
3G Extra (Badische), Yellow R, Rose R, or Violet B, 50 grams of Turkey- 
red oil, 50 grams of glycerol, 50 grams of Ludigol (m-nitrobenzenesulfonic 
acid), and 800 grams of a British gum and starch thickener. The prints 
are steamed for 5 minutes in a Mather-Platt, without pressure, as blinding 
may occur on pressure steaming.° 


342 ACETATE SIE 


When dissolved and cool add 5 grams of dispersol (Duranol) 
dye paste. Print, steam 15 minutes at 100° C. (212° F.) without 
pressure and wash off. 


Discharge Prints 


Davies! states that dischargeable direct cotton colors are being 
dyed on acetate silk which has been saponified either with or with- 
out a protective medium in the saponification bath. Such colors 
are dischargeable with the usual reducing agents, such as a 10 per 
cent solution of Formopon (sodium formaldehyde sulfoxylate), 
though generally somewhat stronger discharge pastes must be used 
and care must be taken in the washing to prevent the whites from 
being sullied. 

When dealing with unsaponified acetate silk, it has been almost 
impossible to obtain good white discharges, and therefore colored 
discharges have been the only really satisfactory ones produced. 
The following dyes are suitable for ground colors if the goods are 
to be subsequently discharged with hydrosulfite : 


Cellutyl Fast Golden Yellow Cellutyl Fast Red D 
Cellutyl Orange 2R Cellutyl Fast Lilac 
Cellutyl Fast Orange G Acronol Brilliant Blue 


Cellutyl Sky Blue 


The regular basic dyes which are commonly used with the sul-_ 


foxylates for color discharges can be used for the production of 
‘colored discharges on acetate silk. Schneevoigt® recommends the 
addition of resorcinol to acetate silk discharge printing pastes con- 


taining Rongalite for use in obtaining white discharges on basic © 


colors. 
The following colors on acetate silk may be discharged to a 
satisfactory white by means of a chlorate discharge: 


Duranol Blue G in light shades Cellutyl Sky Blue 
Duranol Red 2B Cellutyl Fast Blue 
Cellutyl Fast Orange R Cellutyl Fast Gray 
Cellutyl Bright Yellow Cellutyl Fast Lilac 
Cellutyl Bright Red Methyl Violet 2B and 10B 
Cellutyl Bright Green B and Y Acridine Orange L 


It is a peculiar fact that certain colors of this class which theo- 
retically should be readily dischargeable with sulfoxylates and 
are, where applicable, easily discharged on other fibers, cannot be 
discharged by the ordinary sulfoxylate method when dyed on 
acetate silk. 


COLOR PRINTS AND DISCHARGES 343 


The discharge printing of the dispersol dyes on acetate has not 
been very satisfactory, as the reduction of these colors by the usual 
hydrosulfite or sulfoxylate process, such as commonly used on 
cotton, silk, and wool, is not generally effective with the dispersol 
type of dyes on acetate silk; however, some members of the group 
respond to this treatment better than others. The British Dye- 
stuffs Corporation have found that the addition of thiocyanates to 
the reduction discharge printing paste containing sodium sul- 
foxylate, aids materially in the reduction of many colors which it 
was formerly impossible to discharge for some unknown reason. 
Davies' recommends the calcium thiocynate for this process, as in 
the following formula. 

Method No. &4: Discharge Printing Paste for Acetate Silk. 
Fifteen to 20 parts sodium sulfoxylate (Formosol, Rongalite, 
etc.) are dissolved in 75 to 70 parts of a solution of 30 parts of 
gum tragacanth in 1000 parts of water, and cooled. Ten parts 
of 88° Tw. calcium thiocyanate solution are then added.° 

The dyed fabric, without previous preparation, is printed, dried, 
and aged for 3 to 5 minutes in the Mather-Platt ager at 101° C. 
(214° F.). It is then well washed in water at 60° C. (140° F.) 
and dried. 

By this method, the following colors give white discharges on 
acetate silk: 


Cellutyl Fast Yellow C Ionamine MA (only when dyed di- 
Cellutyl Fast Golden Orange rect) 
Cellutyl Orange 2R Ionamine GA (only when dyed di- 
Cellutyl Fast Orange Yellow rect) 

- Cellutyl Fast Orange G and GK Ionamine B developed with B-hy- 
Cellutyl Fast Red D droxynaphthoic acid 
Cellutyl Sky Blue Ionamine GA developed with B-hy- 
Acronol Brilliant Blue droxynaphthoic acid 


_lIonamine A (only when dyed direct) Ionamine Red KA 
Ionamine B (only when dyed direct) | Dispersol Yellow 3G 


* This process is covered by British Patent No. 262,254, November 25, 
1925, to L. Smith and the British Dyestuff Corporation, which states that 
clear white and colored discharge effects on acetate silk dyed with those 
dyes commonly used for this material are obtained in the usual manner by 
means of reducing agents containing sodium formaldehydesulfoxylate, pro- 
vided that thiocyanates such as calcium, barium, and ammonium thiocyanate 
are present. A satisfactory discharge paste contains 15 grams of sodium 
formaldehydesulfoxylate, 70 grams of 3 per cent gum tragacanth solution, 
oy . grams of an aqueous solution of calcium thiocyanate (specific gravity 


344 ACETATE SILK 


Where the above dyes are combined with dischargeable direct cot- 
ton dyes on acetate silk-cotton unions, Method No. 84 gives white 
effects on both fibers. 


——— 


The following substantive dyestuffs, which leave acetate silk 


either white or only slightly stained, are suitable for white dis- 
charges on the accompanying cotton: 


Oxamine Blue B, 3B and GN 

Oxamine Light Blue G (for light 
and medium shades) 

Oxamine Light Blue B and BG 

Oxamine Pure Blue 5B and 6B 

Oxamine Black BHN and RN 

Oxamine Light Gray EB 

Oxamine Dark Blue BG 

Oxamine Blue 4B (for light and 
medium shades) 

Cotton Black AC 


Pyramine Yellow G 

Pyramine Brilliant Orange 3RS 

Oxamine Light Red 4B 

Oxamine Light Red E8B (for light 
and medium shades) 

Oxamine Brilliant Red B (for light 
and medium shades) 

Cotton Fast Red 8BS 

Oxamine Light Pink BX and BBX 

Cotton Pink BN and GN 

Oxamine Brilliant Light Violet B 
and RR 


The following give white discharges in pale shades but in me- 
dium and full shades are suitable only for colored discharges : 


Oxamine Fast Yellow B 
Stilbene Yellow GX and 3GX 
Cotton Orange G and R 


Thiazine Red GXX and R 
Oxamine Violet 
Burl Black B 


Thiazine Brown G and R 


The following acid dyestuffs which leave acetate silk either 
white or only slightly stained are suitable for white discharges on 
the accompanying animal fibers: 


Wool Fast Yellow G 
Supramine Yellow R 
Orange II 
Anthosine 3B 


Scarlet RR 

Supramine Red B 

Neptune Green S10G 

Light Green SF Yellowish 


The following are adapted for the production of colored dis- 


charges : 


Quinoline Yellow and Extra 
Acid Rhodamine BG 


Azocarmine BX 
Acid Violet 4RN 


Special Printed Effects 
British Patent No. 215,860, February 22, 1923, to the Calico 
Printers’ Association and F. Roberts, covers the production of 


pattern effects on fabrics containing rayon, including acetate silk, 
by means of mercerizing agents other than sodium hydroxide, such 


as sulfuric, hydrochloric, phosphoric, or nitric acid, or zine chlo- 


COLOR PRINTS AND DISCHARGES 345 


ride, cuprammonium, or calcium thiocyanate solution. The “mer- 
cerizing” agent may be directly printed on the fabric, or the fabric 
may be first printed with a resist, such as starch or British gum, 
and then immersed in the mercerizing agent. When the fabric 
contains acetate silk, and the latter method is employed, the lim- 
its of treatment are: 1 to 5 seconds with 80 to 168° Tw. (1.140 to 
1.84 sp. gr.) sulfuric acid at 13° C. (55° F.) ; 2 seconds to 2 hours 
with phosphoric acid of 129 to 160° Tw. (1.65 to 1.80 sp. gr.) 
at 12 to 93° C. (53 to 200° F.) ; 1 to 15 seconds in 26 to 40° Tw. 
(1.13 to 1.20 sp. gr.) hydrochloric acid at 18° C. (55° F.); 1 to 
5 seconds in 60 to 84° Tw. (1.30 to 1.42 sp. gr.) nitric acid at 
13° C.; 0 to 15 minutes in cuprammonium solutions containing 2.5 
aieon) per cetit Ol copper at 13 to 82° C. (55 to 180° F.); and 2 
seconds to 1 hour in calcium thiocyanate solutions containing 25 
to 90 grams per 100 cubic centimeters of solution at 138° C. 

According to British Patent No. 237,909, July 29, 1924, to 
Heberlein and Company, printed effects on unions of acetate 
silk with mercerized or unmercerized cotton, wool, silk, or the 
older rayons, may be obtained by printing the material with a 
resist such as glue, alcoholic shellac solution, or/and a thickened 
solution of sodium or potassium carbonate or hydroxide, steaming 
if necessary, and then treating the goods with a solvent for the 
unresisted acetate silk, such as chloroform, acetone, pyridine or 
epichlorohydrin. 

Suitable reserves for this process are materials which have a 
mechanical protective effect or have the property of chemically 
changing the parts of the acetate silk with which they come in 
contact. Mechanical protective agents may comprise materials 
such as glue or shellac, which are insoluble in the acetate silk sol- 
vents used. Chemical protective agents comprise saponifying 
materials such as sodium or potassium hydroxides or carbonates. 
The reserve effect may be further enhanced by dyeing or color 
printing, as by the application of suitable vat dyes in the alka- 
line printing paste, and after the removal of the unreserved ace- 
tate silk, the ground may be dyed a contrasting color. Alkaline 
reserves containing a suitable direct cotton color discharge may 
be printed on dyed materials, etc. 


346 ACETATE SILK 


Another printed effect is covered by United States Patent No. 
1,588,951, June 15, 1926, to C. Dreyfus, assignor to the American 
Cellulose and Chemical Manufacturing Co. This states that union 
fabrics containing acetate silk or similar cellulose derivatives may 
be printed with a mixture containing a solvent for the ester, such 
as lactic acid, an inert powder, such as infusorial earth, and a 
thickening agent such as dextrin. The printed fabric is maintained 
at a temperature not exceeding 125° C. until at least a portion of 
the acetate silk in the printed parts may be removed by washing 
with water. Also see Chapter XX XVIII for other printed effects. 


References 


: aa Davies, American Dyestuff Reporter 14, 887-9 (1925) ; and 15, 202 
(1926). 

2W. Cotton, American Dyestuff Reporter 15, 331 (1926). 

®J. Pokorny, Rev. gen. mat. col. 29, 224 (1925). 

‘G. H. Ellis, J. Soc. Dyers and Colourists 42, 184-6 (1926). 

> British Dyestuff Corporation, “The Dyeing and Printing of Artificial 
Silks,” (1926). 

® A. Schneevoigt, Texrtilber. 7, 354 (1926). 

7™W. Milne, American Dyestuff Reporter 15, 886 (1926). 


a oP 


GHAPTER XXV 


DYEING UNION MATERIALS OF ACETATE SILK WITH 
OTHER FIBERS, OR MATERIALS CONTAINING ACE- 
TATE SILK WHITE OR COLORED EFFECTS 


It is of course very evident that before attempting to dye com- 
binations of acetate silk with any other fiber or fibers, the dyer 
should be proficient in dyeing all fibers concerned alone, as well as 
thoroughly familiar with all of the dyestuffs to be employed, their 
characteristics, cross-dyeing and staining properties on the various 
fibers, etc. Without this complete understanding of the subject, 
it is useless to hope for satisfactory ‘results on a commercial scale. 
For this reason it is only logical that the discussion on dyeing ace- 
tate silk unions should follow that on dyéing acetate silk alone. 

In the dyeing of union materials, every difficulty encountered 
in dyeing the component fibers of the mixture is again met, but 
often in an aggravated form, due to the restrictions caused by the 
other fiber or fibers present. Thus, in dyeing the cotton of cotton- 
acetate silk combinations with direct cotton dyes, even where the 
acetate silk is present only as effect threads, the alkalinity of the 
dye bath must be restricted in order to avoid the saponification 
of the acetate silk.* Again in dyeing the wool in wool-acetate silk 
mixtures with acid dyes, both the temperature and acidity of the 
dye bath are subject to restrictions, due to the presence of the ace- 
tate silk.” 

At the present time, one of the largest uses for acetate silk 
appears to be in obtaining multi-color effects, often in widely 
contrasting colors, in one dyeing process, and on account of. the 
restrictions placed upon the dyeing processes by the properties of 
the fibers involved, a very careful study of the dyestuffs avail- 
able, including all of their properties such as cross-dyeing, ex- 


= See Chapter XIX. 

’ As Lustron is more sensitive to acids than Celanese, particular care is 
necessary in the control of acid baths to be used on materials containing 
Lustron. 


347 


348 ACETATE SiLAs 


haustion, hydrogen ion concentration of the dye bath, staining 
accompanying fibers, fastness, etc., must be made. It is also ob- 
vious, from a study of the properties of the different brands of 
acetate silk, that the properties of the particular variety of acetate 
silk present must not be neglected. For example, Lustron has a 

greater affinity for the basic dyes than Celanese or Rhodiaseta, 
and withstands the action of a boiling dye bath for some time. 
This latter may be a considerable factor in the application of 
certain neutral dyeing acid dyes to wool in wool-acetate silk 
combinations. 

However in spite of all these difficulties, a wide variety of two 
or even more, contrasting color effects are obtainable on acetate 
silk unions containing all proportions of acetate silk, which meet 
all the usual fastness requirements, by the one dye bath process. 
Obviously, this is only possible by a careful study of all of the 
factors involved and dyestuffs available. Even more satisfactory 
results, to meet very exacting demands, are possible by the two 
bath process. In this latter process even incompatible dyes may be 
used and a much better result obtained due to a better control of 
the factors influencing the application of each dyestuff. 

With all the drawbacks, three color combination effects upon 
three fiber materials are possible in some cases in a single bath, 
but are usually a matter of considerable manipulation and are not 
by any means uniformly satisfactory, as it is practically impossible 
to dye all three shades to sample. By means of the two or three 
bath method, even solid colors are obtainable on many three fiber 
combinations containing acetate silk. The difficulty in dyeing wool — 
and true silk at the low temperatures recommended for Celanese 
and Rhodiaseta is of course recognized as one of the very consid- 
erable restrictions along this line. The use of Lustron, with its 
greater resistance to high temperatures in the dye bath, will ob- 
viate this restriction to some extent. 


Protecting Acetate Silk in Boiling Solutions 

In this connection the recently announced methods of conserv- 
ing the luster of Celanese and Rhodiaseta in boiling aqueous baths 
are of particular interest. It was formerly considered impossible — 


DYEING UNION MATERIAL 349 


to treat materials containing these fibers at temperatures above 
about 85° C. (185° F.) in the presence of water without loss of 
luster and other valuable properties. British Patent No. 206,113¢ 
shows how true silk may be degummed in the presence of Rhod- 
jaseta in a boiling soap bath and British Patent No. 246,879 
covers the dyeing and other treatment of materials containing Cel- 
anese in boiling aqueous solutions. Both of these patents are 
based upon the use of a certain minimum quantity of suitable in- 
organic salts in the aqueous liquor. These salts appear to act as 
protective agents, very possibly by retarding the hydrolysis of the 
cellulose acetate, so that the bath may be boiled for some time with- 
out injury to the fiber. In this way it is possible to cross-dye 
Celanese unions with direct cotton or other dyes at the boil. 
Obviously in the case of unions containing Lustron, which with- 
_ stands treatment in boiling water, this method is unnecessary. 

Method No. 85: Cross-Dyeing Celanese at the Boil. Enter the 
union into the direct cotton dye bath at a temperature not over 
82° C. (180° F.) and dye until the bath is nearly exhausted, with 
the usual addition of Glauber’s salt. When the dye is nearly ex- 
hausted, add sufficient concentrated solution of Glauber’s salt to 
bring the total amount of this constituent to about 30 per cent, on 
the weight of the dye bath. Raise the temperature to boiling and 
boil for an hour. In case only a half hour’s boiling is necessary 
a slightly lower percentage of Glauber’s salt may be used. For an 
hour’s boiling, the dye bath should contain about 2.5 pounds of 
Glauber’s salt per gallon of liquor. After this dyeing, rinse well 
and fill in the Celanese to shade in a second dye bath at a tempera- 
ture below 80° C. (175° F.). The luster of the Celanese should 
be unaffected. It has also been recommended! to use a 10 per cent 
solution of ammonium sulfate in the same way, in place of the 
sodium salt. 

This process is covered by British Patent No. 246,879, of June 
31, 1924, to A. J. Hall and the Silver Springs Bleaching and Dye- 
ing Company, which states that acetate silk may be treated for 
prolonged periods in boiling aqueous liquors without becoming 
curly and wool-like, and without loss of luster and transparency, 


“See Chapter X. 


350 ACETATE SILK 


if the liquor contains not less than a certain minimum amount of a 
protective salt, the minimum quantity being dependent on the 
particular salt or salts usd. Suitable salts include sodium, ammo- 
nium, calcium, magnesium, barium, aluminum, strontium, and po- 
tassium chlorides; ammonium, sodium, copper, magnesium, zinc, 


and potassium sulfates ; sodium sulfite, alum, chrome alum, sodium — 


chlorate, potassium oxalate, and sodium nitrate. The dyeing prop- 
erties of the acetate silk are not altered by such treatment. In gen- 
eral, 10 to 30 per cent solutions of the protective salts are used and 
they are particularly useful in the treatment of acetate silk mate- 
rials containing other fibers, or other treatments in which it is nec- 
essary to use boiling liquors, or other liquors at a temperature 
exceeding 85° C. (185° F.). The process has particular applica- 
tion in the dyeing of acetate silk-wool union textile materials. 


Canadian Patent No. 260,319, April 27, 1926, to H. Dreyfus ap- — 


pears to cover the same process. Also see British Patent No. 
206,113. 

Much has already been said concerning the dyeing of acetate 
silk unions under the subject of the various classes of dyes. In 
dyeing cotton or wool goods with an acetate silk thread stripe or 
effect, it is not always necessary and is sometimes not desirable 
to leave the acetate silk white. When this is the case an even 
wider range of direct, acid or other dyes than those mentioned may 
be used on the fibers accompanying the acetate silk. However, 
in case the acetate silk is stained by the dyes used on the other 
fibers, care must be taken in buying the dye that various shipments 
of the dye, even from the same manufacturer, stains the acetate 
silk to the same extent. For this reason, it is usually much safer 
and more satisfactory to use a cotton or wool dye which does not 


it atte in ei ee 


stain the acetate, and then dye the acetate silk stripe or effect with — 


some other suitable dyestuff, in the same dye bath, if desired. 


In selecting direct cotton or, in fact, dyes of any other class — 


which do not stain acetate silk, it should be remembered that in the © 


case of most of these dyes, it is not the direct dye itself which 
stains the acetate silk, but some uncombined base, basic impurity, 
or even a basic dye, the latter probably added for shading purposes. 
From this it can readily be seen that while one batch of a direct dye 


DYEING UNION MATERIAL 351 


may stain the acetate silk very little or not at all, the next lot, 
even from the same source, may vary considerably in this respect. 
Most of the special “acetate white” direct dyes offered on the 
market are merely a purified grade of some older and usually well 
known direct dye. The same statement applies to the acetate- 
white dyes of other classifications. or this reason, in buying 
direct dyes to be used on materials containing acetate silk, each 
shipment of dyestuff should be carefully tested out in the labora- 
tory before its use is attempted in the plant. 

Many direct cotton blacks stain acetate silk a yellow or orange 
color, due to the presence of basic yellow or orange dyes used to 
give depth and fullness. In this way, at least one hoisery-dyeing 
plant in America is using a direct dye which stains acetate silk on 
cotton-acetate silk so as to give two-colored-effect hoisery. In 
this case the color on the cotton and acetate silk are sufficiently 
different to give a good two-color effect in the one dye bath at an 
extremely low price. Possibly a dyestuff such as Chlorazol Black 
E Extra could be used for this purpose. However, while this 
scheme is very cheap, it will hardly be found satisfactory on the 
better class of goods which must be dyed to sample. 

In connection with Chapter XIII on the Acid and Mordant 
Dyes on Acetate Silk, many acid dyes are mentioned which dye 
acetate silk, but which in most cases give a different shade, usually 
of the same color, on wool or true silk. A suitable selection of 
‘dyes from this group could be used for more or less contrasting 
shades on acetate silk-wool or true silk unions. By using a union 
dye which stains or dyes acetate silk on combinations of acetate 
silk with both cotton and wool and/or true silk, still further more- 
or-less-contrasting shades with one dye in a single dye bath, are 
possible. 


Know Your Union 


It is of course of prime importance that all of the various 
fibers accompanying the acetate silk be identified, as mentioned in 
Chapter V under the identification of the rayons, and their pre- 
vious treatment (such as the mercerization of cotton") be de- 


*See Chapter VI. 


352 ACH TATE CSIC 


tected, as well as the particular brand of acetate silk used, if pos- 
sible, before attempting to dye the goods. Perhaps the best and 
quickest method of detecting the presence of rayon is by means 
of the microscope. Either a large sample of the goods may be 
placed upon the stage, or a few of the suspected fibers mounted 
on a slide by the usual quick process. In this manner cotton, wool, 
linen and bast fibers can be recognized at a glance, and real silk 
distinguished from rayon with very little more difficulty. 

If a chemical test is desired to confirm the microscopic findings 
a sample may be boiled with sodium hydroxide solution. This 
dissolves the animal fibers, true silk, and wool, leaving the vege- 
table fibers and all of the rayons. The burning test is a quick 
and convenient method of distinguishing between true silk and 
rayon. True silk gives the characteristic odor of burning proteins, 
while the rayons, with the exception of acetate silk, burn very 
much like cotton. The acetate rayon fuses rather than burns, as 
described under the burning test for acetate silk, Chapter V. 

It has also been stated that if a sample of union goods contain- 
ing rayon is heated to 200° C. (392° F.) for ten minutes, the 
rayon will be completely carbonized and may be dusted out of the 
sample by rubbing, while the natural fibers (cotton, wool and true 
silk) are unchanged. A complete review of the methods of iden- 
tifying the different types of rayon is given in Chapter V. 


References 
1F. M. Stevenson, Dyer and Calico Printer 55, 86-8 (1926). 


se . 


CHARTER XXXVI 
THE BASIC DYES ON ACETATE SILK UNIONS 


The Methods of Dyeing Combinations of Acetate Silk with 
Cotton, Wool, or True Silk with Basic Dyes. 


Waite the basic dyes are not generally used on the acetate silk 
of acetate silk unions for multicolor effects, at the present time, 
due to the superior qualities of some of the special acetate silk 
dyes, a knowledge of their behavior in this respect may be of 
value for certain purposes. In this connection the reader should 
not neglect Chapter X, on the Basic Dyes on Acetate Silk. 

In dyeing cotton-acetate silk unions or combinations of acetate 
silk with other rayons, it is sometimes easy to secure a wide variety 
of two color effects by using basic dyes on the acetate silk and 
direct cotton dyes on the cotton or rayon. If Lustron is used, it 
is especially easy to secure contrasting colors, due to its high 
affinity for the basic dyes. Sometimes it is possible to use both the 
basic and direct dyes in the same dye bath, but usually better re- 
sults are obtained by using separate baths. If only one bath is 
used, it is generally best to apply the basic dye first, and when it is 
about exhausted, to add the direct dye to the bath. If solid, in- 
stead of contrasting shades are desired on the two fibers, a more 
careful selection of the dyes must be made and more care used in 
their application. 

In selecting the direct cotton dyes for use upon rayons or cot- 
ton-acetate silk unions, care should be taken to select only those 
dyes which do not stain acetate silk. For this reason only dyes 
specially prepared for this particular use should be employed, as 
mentioned in the previous chapter. However, there are now many 
lines of cotton dyes prepared particularly for use with acetate silk 
which do not stain it.* 

In cross-dyeing acetate silk unions containing cotton or rayon, 
it is important to dye the acetate silk first, or the substantive dyes 


"See Chapters XX XIII and XXV. 
Oo 


354 ACETATE SILK 


may mordant the basic dyes on the cotton, thereby causing a 
staining or dyeing of the cotton or rayon, with the basic dyestuff. 
In applying the basic dyes to acetate silk-cotton or rayon unions at 
low temperatures, the basic dyes of course stain both fibers, but as’ 
the temperature is raised the color feeds onto the acetate silk 
(Lustron) from the cotton or rayon, until at a sufficiently high 
temperature, especially in the presence of acetic acid, the other 
fibers are clear. Sometimes a fairly high temperature is necessary 
to clear the fibers accompanying the acetate silk, and in this case 
the better resistance of Lustron to high temperatures,is an advan- 
tage in its favor. Plenty of salt should be used in cross-dyeing the 
cotton, so as to avoid bleeding from the basic dyes. 

As an illustration of the two color dyeing process on acetate 
silk-cotton unions, the following formula gives a bright peacock 
blue color on Celanese, while the cotton is dyed a grey: 


Capri Blue GON 1.5 per cent, 
Acetic or formic acid (100%) 2 cubic centimeters per liter, and 
Sodium chloride 20 per cent. 


Enter the goods at 45° C. (113° F.) and dye at 45 to 80° C. 
(113 to 176° F.) for about one hour or until the desired shade 
is obtained. If necessary the cotton may be cleared as in Methods 
No. 111, No. 112, or No. 113. Then cross-dye the cotton with 
CR Chlorazol Fast Gray 0.3 per cent and 


Sodium chloride 5.0 per cent. 
Enter cold and dye at 50° C. (122° F.) or below for about three- 


quarters of an hour. 


Where the cotton in the acetate silk union is to be left white, 
Chase! recommends entering the Lustron-cotton union into a cold 
or lukewarm dye bath containing 5 to 10 per cent of acetic acid, 
on the weight of goods. The dyestuff, in solution, is then added 
and the temperature gradually raised to 66 or 77° C. (150 or 170® 
F.). Salt may also be added as a retarding agent. If the cotton 
is stained it can usually be cleared by Method No. 111, but Chase 
recommends the use of lactic acid in place of the acetic acid; or by 
Method No. 112. 

In spite of the comparatively high affinity of the basic dyes for 
acetate silk, Blackshaw? reports that due to the lack of affinity of 


BALD YES 355 


acetate silk for the usual basic dye mordant, i.e., tannin and tartar 
emetic, it is possible to mordant the cotton of Celanese-cotton 
unions and by applying the basic dyes in the presence of 5 per 
cent of formic acid, obtain white acetate silk effects with Celanese ; 
but this effect is not possible with Lustron. He states that acetic 
acid cannot be substituted for the formic acid above. It is very 
doubtful if this procedure would be as successful on Lustron-cot- 
ton unions as in the presence of Celanese, and very probaby the 
results, as regards the staining of the acetate silk, vary considerably 
with the particular basic dye used. 

, Method No. 86: Dyeing Acetate Silk-Cotton Unions With Basic 
and Direct Dyes. Dye the acetate silk with basic dyes in the 
presence of acetic acid, as in Methods No. 24 or No. 25. Then 
fill up the cotton with suitable direct cotton dyes in the usual man- 
ner in a dye bath containing salt, soap, or Turkey-red oil, and a 
little soda, if necessary. 

Method No. 87: Dyeing Acetate Silk-Cotton Unions With Basic 
Dyes Only. First mordant the cotton of the union with tannin and 
antimony in the usual manner. In the case of Lustron, both fibers 
of the mordanted union may then be dyed with suitable basic dye- 
stuffs in one operation. 

Method No. 88: Janus Dyes on Lustron-Cotton Unions. The 
Lustron Company states that Lustron-cotton unions may be dyed 
solid shades by means of the Janus dyes. The affinity of the 
Janus dyes for cotton varies considerably with the condition 
of the cotton, 7.e., unbleached, bleached, or mercerized. Their 
affinity for cotton is greatest somewhat below the boil, while 
their affinity for Lustron increases with the temperature up to 
the boiling point. In this manner, by properly regulating the 
temperature of the dye bath, the dyer can control the dyeing so 
as to obtain either solid or varying shades upon the two fibers. 
However Hall states that the Janus dyes, as well as the Acridene 
and Azine dyes, are not fast upon acetate silk. He probably 
refers particularly to Celanese. 

Method No. 89: Dyeing Acetate Silk—True Silk Unions With 
Basic and Acid Dyes. In dyeing acetate silk-real silk unions, 
using basic dyes for the former and acid dyes for the true silk, 


356 ACETATE SILK 


the two dyes can sometimes be applied in a single dye bath, with 
acetic acid. In using this single bath method, it is of course im- 
perative that dyestuffs be selected which do not react with each 
other in the dye bath. For this reason it is usually best to use 
two dye baths, applying the basic dyes as in Methods No. 24 or 
No. 25, and then dye the true silk with acid dyestuffs in a fresh 
acetic acid dye bath, by the usual methods. After dyeing, it is 
usually desirable to give the material a light soaping, as this assists 
in clearing the colors. The Gyco Neutral and Kaline dyes, de- 
scribed in Chapter XXXIV, may be particularly useful in this way. 


Three Color Combinations 


In dyeing three color combinations, such as acetate silk, viscose 
and true silk, using basics on the acetate silk, the acetate silk 
should be dyed first in a slightly acid bath, the viscose second with 
direct dyes using salt in an alkaline dye bath, followed by acid 
dyes for the real silk, in the presence of both acetic acid and salt. 
On account of its higher resistance to alkalies and high tempera- 
tures, and its high affinity for basic dyes, Lustron is probably better 
suited for this class of work than some of the other varieties of 
acetate silk. 

Method No. 90: Colored Effects on Acetate Silk-Cotton-True 
Silk Unions. The acetate silk (Lustron) may be dyed as in 
Methods No. 24 or No. 25, with acetic acid. If a white true silk 
effect is desired, clear this fiber in a weak acetic acid bath, as in 
Method No. 111; wash and rinse in a dilute sodium bicarbonate 
bath, as in Method No. 113. Then dye the cotton with direct cot- 
ton dyes which do not stain real silk, in a bath containing salt, 
soap, and a little soda, if necessary. 

Method No. 91: Three Color Effects Upon Acetate Silk-Cotton- 
True Silk Combinations. Proceed as in Method No. 90 and then 
dye the true silk as in Method No. 89. 

Method No. 92: Three Color Effects Upon Acetate Sulk-Cotton- 
True Silk Combinations. Dye the acetate silk (Lustron) and true 
silk as in Method No. 88. This will give the same or different 
colors on the acetate silk and true silk, leaving the cotton white 
or stained, depending upon the particular dyes used. The cotton 


sy SMG DW aas 357 


may be cleared by Method No. 112, and then dyed the same or a 
different color by means of a direct cotton dye which does not stain 
real silk, in the usual manner. 


. Dyeing Acetate Silk-Wool Unions With Basic Dyes 


Acetate silk-wool unions are more difficult to handle in dyeing 
than acetate silk-cotton or rayon combinations. While it is not 
difficult to find acid and other wool dyes which do not stain acetate 
silk, most of the acetate silk dyes and practically all of-the basic 
dyes, stain or dye wool, and in many instances the dyed wool is a 
different color from that of the acetate silk. Most of the acid dyes 
which dye acetate silk give different shades on these two fibers. 
Some basic dyes such as Magenta and Malachite Green give ap- 
proximately the same shade on acetate silk and wool, but at low 
temperatures the wool is dyed a deeper shade. Increased acidity, 
with acetic acid, and higher temperatures tend to feed the basic 
dyé onto the acetate silk. 

Method No. 93: Basic Dyed Acetate Silk-Wool Unions. The 
acetate silk (Lustron) may be dyed with basic dyes as in Methods 
No. 24 or No. 25 with acetic acid and the wool may be dyed with 
an acid dye in the same or a fresh bath, as in Method No. 89. 
Many other acetate silk dyes are particularly adapted for dyeing 
two or more color effects upon acetate silk unions, and these will 
all be considered later under the other dyes, in their appropriate 
order. 

Method No. 94: After-treating heron Always after treating 
Lustron with an acid solution, such as in applying the basic dyes 
in an acetic acid bath, it should receive an after-treatment for 15 
to 30 minutes in a cold solution containing 0.25 to 1 gram of 
sodium bicarbonate (baking soda) per gallon of water. The Lus- 
tron should then be hydroextracted and dried without rinsing. 
This insures that no acid remains in the goods. In selecting dyes 
for use upon Lustron or unions containing it, only those should be 
used which do not strip or bleed with this aftertreatment. 


References 


1W. W. Chase, Textile World 71, 557-8 (1927). 
mrt, Blackshaw, Dyer and Calico Printer 55, 192-3 (1926). 


CHAPTER Xs 


THE ACID: AND MORDANT TYPE OF DYES ON ACE- 
TATE SILK-COTTON UNIONS 


It is of course obvious that the acid and certain mordant dyes 
may have a particular field of usefulness upon acetate silk and 
wool or true silk unions. As explained in connection with the use 
of basic dyes upon acetate silk-wool unions, most of the acetate 
silk dyes stain or dye wool, particularly in this case. However, 
a given dye does not always give the same shade or even the same 
color upon both the acetate silk and the accompanying animal fiber. 
Of course the colors or shades ultimately obtained from any one 
dye or combination of dyes are entirely dependent upon the com- 
position, concentration, and temperature of the dye bath. There 
is no difficulty in finding acid and mordant dyes for use upon 
wool which do not dye the acetate silk, but the dyeing of wool and 
cotton materials containing acetate silk white effects will be consid- 
ered later. 

In the case of acetate silk-cotton unions, it is obvious that only 
in a very few cases of “union” dyes would the acid or mordant 
dye be applicable to the cotton. Where they are to be applied to 
the acetate silk in these unions, Method No. 25 may be used.* 
The Lustron Company state that Acid Rhodamine 3R, Azo Yellow 
Ab5W or Indian Yellow GA, Coomassie Fast Violet 10BP, Chrome 
Orange R also known as Alizarine Yellow R or Alizarol Orange 
R, Pontachrome Yellow 3R, Alizarine Yellow 2G or equivalent, 
Alliance Fast Brown 5G, Terra Cotta RS, Anthracene Browns and 
Blues, as well as Modern Violet and Violet PPH or Prune Pure, 
may be used for this purpose. Many of the basic dyes may be used 
with them; for instance, Alizarine Yellow R and either Victoria 
Green WB or Methylene Green B, may be applied in the same 
bath, by Method No. 25 to obtain a light fast green. 


* Also see Chapter XIII. 


358 


ACID AND MORDANT TYPES 359 


When using a basic dye with a mordant dye, it is best not to 
add any salt to the dye bath until after the basic dye has been ex- 
hausted therefrom, unless it is desired to restrain the rate at which 
the basic dye feeds on the acetate silk, as salt has a marked retard- 
ing action on the basic dyes for acetate silk. Possibly a better 
way would be to apply the basic dye first cold, with or without 
salt and acetic acid; then when the bath is exhausted, the mordant 
dye may be added to the dye bath and the dyeing continued to 
shade. With most of the mordant dyes on acetate silk, a chrome 
after-treatment is of no particular benefit. The addition of chrom- 
ium acetate to the dye bath, when applying the Gallocyanines,” 
will improve their fastness to washing. Where the cotton is 
stained, it may be cleared by Method No. 111 or this treatment 
may be followed by Method No. 113, Chapter XXXV. 

In a few cases solid colors may be obtained on acetate silk- 
cotton unions, with combinations of acid and direct cotton dyes. 
For instance, a solid yellow color may be obtained with Fast 
Yellow 5GW and Citronine Y conc.; a solid brown shade with 
Alizidine Brown M, Chlorazol Brown M and Chlorazol Brown 
LF; or a solid blue with Chlorazol Sky Blue GW and Prune Pure. 
Many of the dyes discussed elsewhere, such as some of the Ace- 
tate and Cellutyl dyes, are also members of the acid and mordant 
classification of dyes and‘are applicable to the acetate silk of 
unions containing it. In the case of acetate silk-wool unions, un- 
doubtedly both fibers would be dyed. However, as a class these 
older dyes of this classification are rapidly being displaced for use 
on acetate silk by the special new dyes for acetate silk, some of 
which apparently belong to the acid and mordant group. Also 
see Method No. 41 of Chapter XIII. 

The Setacyl Direct dyes of the Geigy Company are recommended 
for use on acetate silk-cotton or rayon unions in connection with 
the Art Silk CW dyes of the same company, to produce multi- 
color or shot effects at a very low dyeing cost. They withstand 
cross-dyeing well, with only a slight staining of the cotton, or 
viscose in some cases. | 


"See Chapter X. 


360 ACETATE SILK 


While the Cellit Fast dyes as a class usually stain cotton, wool, 
and true silk to some extent and are therefore not so well suited 
for use where the fiber accompanying the acetate silk is to be dyed 
in lighter, contrasting shades, they find a certain use where the 
accompanying fibers are to be dyed in similar or darker shades. — 
Where only light shades are applied to the acetate silk, the cotton — 
or viscose present in unions can usually be cleared up by a soaping — 
as directed under Clearing Unions, Chapter XXXV. 

Method No. 95: The Cellit Dyes on Acetate Silk Cotton Unions. — 
Where these dyes are to be applied on cotton-acetate silk materials — 
with a colored warp, the warp should be dyed in the hank. Ing 
case a black warp is desired, 7.5 per cent of Katigen Deep Black 
B gives very good results. After weaving, the acetate silk may be 
dyed as in Method No. 46, then rinsed and washed in a soap bath - 
at 40 to 49° C. (105 to 120° F.). This washing clears the cotton — 
or viscose, which if still in the white state, may then be dyed in © 
a fresh dye bath at 43 to 49° C. (110 to 120° F.), with an addition © 
of about 20 per cent of calcined Glauber’s salt. ‘ 


CEAPILER XXVIII 


Peewee UR DYES ON ACETATE SILK-COTTON 
UNIONS 


THE use of the sulfur dyes on acetate silk was mentioned in 
Chapter XV. Many sulfur dyes, even blacks, may be applied to 
acetate silk-cotton unions, leaving the acetate silk clean, if applied 
at low temperatures in short baths containing as little sodium sul- © 
fide and alkali as possible to hold the dye in solution. Method No. 
96 has been recommended for Lustron-cotton unions. Where the 
acetate silk of the acetate silk-cotton union is to be dyed with dis- 
persol dyes, it is usually best to dye the acetate silk first and then 
cross-dye the cotton either in the padder or jig. 

Method No. 96: Sulfur Dyes on the Cotton of Acetate Silk- 
Cotton Combinations. For 100 pounds of dye bath, use 1 pound 
of Sulfogene Carbon Black H, 2 to 2.25 pounds of sodium sulfide 
crystals, 0.25 pound of sodium carbonate, and 0.25 to 0.5 pound 
of salt. Dye at about 20° C. (68° F.) or not over 24° C. (75° F.). 
A full shade is obtained in an hour or an hour and a quarter. 

British Patent No. 214,330, January 18, 1923, to the Clayton 
Aniline Company covers the use of waste sulfite cellulose liquor, 
or its constituents, which comprise sodium lignin sulfonate, resin- 
ous matter, and various sugars, to protect the acetate silk from the 
saponifying action of sodium sulfide and other alkalies’ in dye 
baths. Its use is particularly recommended in applying sulfur 
dyes to acetate silk-cotton unions where it is desired to leave the 
acetate silk white. 

In this manner 10 parts by weight of the union, containing not 
more than 10 per cent of acetate silk may be dyed in a 60 to 1 dye 
bath containing 2 parts of Pyrogene Deep Black A paste, which is 
equivalent to 1 part of the pure dry dyestuff, 2 parts of sodium 
sulfide crystals, 0.2 part of sodium carbonate, 6 parts of Glauber’s 
salt and 2 parts of cellulose-sulfite waste liquor of 1.28 specific 
gravity. The material is entered at 50 to 60° C. (122 to 140° F.), 


361 


362 ACETATE SILK 


and after the temperattire has been raised to 80° C. (176° F.), it 
is dyed at this temperature for one-half hour. The material is 
then well rinsed. Where it is desired to leave the acetate silk 
white, Pyrogene Green 3G, Pyrogene Deep Black A, and Pyrogene 
Cutch 2GR are recommended. 

According to British Patent No. 238,721, September 19, 1924, to 
the British Dyestuffs Corporation and H. D. Mudford, the ad- 
dition of a suitable quantity of an ammonium salt, e.g., ammonium 
chloride or sulfate, to the ordinary sulfide dye bath considerably 
reduces its hydrolyzing action on acetate silk. In this way it is 
possible to dye the cotton in acetate silk-cotton unions in fast 
heavy shades with sulfide dyes and leave the acetate silk unstained. 
This patent refers to British Patent No. 19,473, September 5, 1914, 
to E. Lodge and J. M. Evans, which covers the dyeing of animal 
fibers, union goods, and rayons with sulfide dyes in the presence of 
an alkali sulfide and a neutral ammonium salt. 

Method No. 97: Sulfur Dyes on the Cotton of Acetate Suk-— 
Cotton Unions with Ammonium Sulfate. Two parts of Thional 
Black GSX conc. are dissolved by boiling with 4 parts of sodium — 
sulfide crystals in 80 parts of water and placed in the dye baths 2 
solution of 2 parts of ammonium sulfate in 20 parts of water is 
then added and the scoured, thoroughly wet-out goods entered. 
The dyeing is carried out at 80 to 85° C. (176 to 185° F.), after 
which the material is thoroughly rinsed with hot water until free of 
alkali and adhering dyestuff. Thional Black OG, Liquid Sulfur | 
Blacks G, L and R, Thional Browns P and B, Thional Corinth 
GX, and Thional Greens B and 2G, may also be used in the same 
way. 

Possibly the patent of F. L. Remlin and the Du Pont de Nemours 
Company, United States Patent No. 1,551,330, August 25, 1925, 
may also be useful in applying the sulfur dyes to unions contain- 
ing acetate silk. This patent covers the application of sulfur dyes 
to real silk in dye baths of reduced alkalinity, by the addition of 
sodium hydrosulfite, sodium bisulfite, and 0.75 to 5.0 per cent, on — 
the weight of the dye bath, of a “gum soap.” Method No. 98 
covers the use of a special “Reserve Salt.” 

Method No. 98: Kryogene Black TBOC on Cotton-Acetate Sik 


SUILPUR DYES 363 


Umons. Prepare the dye bath with 6 grams of Kryogene Black 
TBOC, 16 grams of sodium sulfide crystals, 2.5 grams of calcined 
soda, 30 grams of calcined Glauber’s salt, and 60 grams of Reserve 
for Acetate Silk, per liter of liquor. Dye at 40 to 50° C. (104 to 
122° PF.) for an hour. Squeeze direct from the dye bath and rinse 
thoroughly at once. The white effect is improved by a subsequent 
soaping at 50 to 60° C. (122 to 140° F.) in a bath containing 5 
grams of olive oil soap per liter. When a standing bath is used, 
cut the sulfide to a half or a third of the amount used in starting. 
and add the Reserve Salt and Glauber’s Salt according to the 
volume of liquor removed from the dye bath. 

Besides the sulfite cellulose waste liquor (Protectol) and am- 
monium sulfate which have been mentioned as protective agents 
in the application of the sulfur dyes to acetate silk-cotton unions, 
casein, glucose and cresolsulfonic acid, etc., have also been men- 
tioned, but do not appear to have found much use in commercial 
practice. Sodium phenolate has been recommended as a leveling 
agent for these, as well as other dyes, in an alkaline dye bath. 


CHAPTER XXIX 


THE VAT DYES ON THE COTTON OF ACETATE SILK- 
COTTON UNIONS 


WHERE very fast-to-light dyes, such as most of the dispersol 
products, are used on the acetate silk of acetate silk-cotton unions, 
in order to obtain a correspondingly fast color on the cotton, it iS 
necessary to dye it only with vat dyes. On account of the sensi- 
tiveness of acetate silk to alkalies and the necessity of using a more 
or less alkaline dye bath in the application of the vat dyes to all 
textile fibers, at first thought it might appear to be an impossibility ; 
but as usual, the difficulties have been overcome to a large extent, 
and a selected list of suitable vat dyes may now be applied to 
cotton, in the presence of acetate silk, by methods somewhat simi- 
lar to those used in vat-dyeing wool or silk. 

In applying the vat dyes to the cotton of acetate silk-cotton 
unions, it is, of course, necessary first to scour the union by the 
method generally recommended for the particular type of acetate 
silk used in the union. It may then be bleached by either the hypo- 
chlorite or peroxide method, as described under bleaching,* and 
if hypochlorite was used is given the usual antichlor treatment. 

In the application of the vat dyes to acetate silk-cotton unions, 
only the two-bath method is used, owing to the fact that the color 
of many of the dispersol colors on acetate silk is altered on cross- — 
dyeing the cotton in a hydrosulfite dye bath. According to the — 
dyeing methods of the manufacturers of Celanese, the vat dyes — 
suitable for application to cotton by their methods, may also be# 
applied to wool and true silk. Probably in many cases the methods | 
previously proposed by Scottish dyes may also be applicable to 
vat-dyeing wool and true silk, either alone or in combination with © 
acetate silk. According to British Patent No. 214,112, as well as — 
many other patents mentioned in connection with the vat dyes on — 


aSee Chapter IX. 
364 


VAT DYES 365 


acetate silk,” certain vat dyes may also be applied to acetate silk 
from a hydrosulfite vat, in which case it may be possible to dye 
acetate silk unions in a single hydrosulfite dye bath. Undoubtedly 
the Ciba dyes may be applied to both fibers of acetate silk-cotton 
unions by Method No. 54. 


Caldeon Vat Dyes on the Cotton or Viscose of Acetate Silk 
Unions 


The cotton or viscose silk is always dyed before the acetate silk 
and the methods used are similar to those normally adopted in 
dyeing cotton except for certain modifications which have to be 
introduced to avoid any deterioration in the acetate silk. As the 
acetate silk is easily hydrolyzed by caustic alkalies, the vat-dyeing 
operation must be carried out at about 25° C. (77° F.). The cold 
dyeing Caledon dyestuffs are consequently the most suitable. Most 
of the hot or medium dyeing dyestuffs, however, may be used 
although some loss of dyestuff must be expected with these latter. 
It is not generally advisable to dye in deeper shades than 10 per 
cent as it is difficult to obtain these economically without staining 
the acetate silk. The methods to be used with the various Caledon 
dyes can be seen from Table LVI. 


TABLE LVI 
VATTING TEMPERATURES FOR THE CALEDON Dyes 
Vatting Vatting 
Temp. Temp. 
a Group ee. Group 

Cal. Blue GC. 120 1 Cal. Green B. 140 1 
Cal. Blue GCD. 120 1 Cal. Gold Orange 
Cal. Blue GCP. 120 | G. 140 1 
Cal. Blue R. 140 1 Cal. Jade Green 110 i 
Cal. Blue RC. 120 1 Cal. Orange RRT. 140 1 
Cal. Blue RR. 120 1 Cal. Purple R. 140 1 
Cal. Brill. Blue R. 140 1 Cal. Red BN. 80-100 2 
Cal. Brill. Purple RR. 140 1 Cal. Red FF. 120 3 
Cal. Brill. Violet R. 105 3 Cal. Red 5B. 120 3 
Cal. Brown B. 140 1 Cal. Red Violet 
Cal. Brown G. 120 3 2 RN. 80-100 2 
Cal. Brown KT. 80-100 2 Cal. Violet RN. 120 2 
Cal. Brown R. 105 3 Cal. Yellow G. 140 1 
Cal. Dark Blue B. 140 1 3 


Cal. Yellow 3G. 105 


"Chapter XV. 


366 ACETATE SILK 


When the material is to be dyed in the form of cops, cheeses, 
beam-warps, or in the piece, the composition of the dye bath for — 
100 pounds of material, i.e., for material containing 100 pounds — 
cotton, can be read off from Table LEViG 


{ 
\ 


TABLE LVII 
COMPOSITION OF THE DYE BATH FOR THE CALEDON Dyes IN MACHINES 


Group 1 Group2 Group 3 


i a es 
Water (British Gallons) 50-80 50-80 50-80 
Caustic soda solution 53°Tw. (pints) 7-9 3.5-4.5 + 5.9 
Caustic soda solution 73°Tw. (pints) 5-7 2.5-3 3.5-4.5 
Hydrosulfite conc. powder (pounds) 1.5-2.5 15-275 1-2.5 


Giaubers Salt Crystalline (pounds) 10.-20 2.5-10 
a 


Method No. 99: The Caledon Dyes on Acetate Silk Unions by — 
Machine. After the material has been well wet-out at a tem- 
perature not exceeding 79° C. (170° F.), the machine is filled with 
the softest water obtainable, one-third of the above quantities of a 
caustic and hydrosulfite added, and the machine run for a short © 
time. In the meantime the dyestuff is dissolved separately. The 
paste is stirred with about ten times its quantity of water, the 
remainder of the caustic and hydrosulfite added, the temperature 
raised to that given in Table LVI for vatting, and this liquor, 
when the dyestuff is in solution, is passed into the dye bath through 
a fine sieve. 

In the case of yarn dyeing, after the liquor has been run off or — 
the yarn lifted, it is of advantage to see that the liquor still in the 
yarn is quickly removed, ¢.g., with compressed air, or better, with 
a vacuum pump. When dyeing beam-warps with Caledon colors 
requiring an addition of salt, this should not exceed 7 pounds per 
100 gallons of dye bath. | 

Method No. 100: The Caledon Dyes on Acetate Silk Union 
Yarns in the Open Beck. The dye vat is prepared with about 180 _ 
gallons of water, 1 to 2 pints of 53° Tw. caustic soda solution, and 
0.5 to 1 pound of hydrosulfite concentrated powder. The dye bath | 
is then heated to the temperature given in Table LVI. The dye-_ 
stuff is dissolved in 15 or 20 gallons of water with the remainder | 
of the caustic solution, hydrosulfite, etc., as shown in Table LVIII. 
The dyeing is carried out cold. 


VAT DYES 367 


TABLE LVIII 
COMPOSITION OF THE DyE BATH FOR THE CALEDON DYES IN THE OPEN BECK 


Group 1 Group 2 Group 3 


Water (British gallons) 200 200 200 
Caustic soda solution 53°T w. (gallons) 2 if 0.2-0.6° 
Hydrosulfite Concentrated Powder (lbs.) 2-2.25 2.25-2.5 1-4 


Glauber’s salt crystals (Ibs.) 10-40 10-80 


_°Caldeon Brilliant Violet R requires 33 per cent more caustic soda solu- 
tion than the amount given above. 


After dyeing, the material is wrung and allowed to oxidize for 
20 minutes. It is then rinsed absolutely free from alkali as this 
may hinder the exhaustion of the Celatene dyes. If necessary a 
small amount of acid may be used for this purpose. This acid 
does not interfere with the dyeing of the Celatene dyestuffs. When 
free from alkali the goods are dyed by the methods given for the 
Celatene dyes on acetate silk, Chapter XXII. 

After exhaustion has taken place the goods are withdrawn from 
the dye bath, wrung lightly and soaped for 15 minutes in a 60° C. 
(140° F.) soap bath containing 10 pounds soap per 100 British 
gallons. This soaping serves a triple purpose, and is essential for 
bright, clean-cut effects. 


(a) It clears the viscose of a certain amount of superficial, 
loosely attached Celatene dye. 

(b) It clears the acetate silk of a certain amount of superficial, 
loosely attached vat dye. 

(c) It brightens both the vat color on the viscose and the Cela- 
tene color on the acetate silk. 


After soaping, the goods are washed free from soap (given a slight 
sour in the case of Caledon Red FF, Celatene Fast Light Brown, 
Celatene Fast Light Yellow and Celatene Gold Orange), wrung 
lightly, and dried. 


The Anthrene and Thianthrene Dyes 
Certain Anthrene and Thianthrene dyes of the Newport Chemi- 
cal Works have also been recommended for use upon the cotton 
of acetate silk-cotton unions, especially in combination with the 


368 ACETATE sits 


Celanthrene dyes of the same company. The Anthrene dyes are 
very similar to the Caledon dyes mentioned above and undoubtedly 
they may be applied by the methods given for the Caledon dyes. 
On account of the restrictions imposed by the presence of acetate 
silk, the following vat dyestuffs have been selected as the most 
suitable for this purpose; however, others may be used with the 
proper methods and care: 


Anthrene Red 3BN paste Anthrene Golden Orange RRT paste 
Anthrene Violet BNX paste Anthrene Golden Orange G paste 
Anthrene Brown BB paste Anthrene Violet 2R paste 

Anthrene Jade Green paste Thianthrene Pink FF paste 
Anthrene Blue GCD paste Thianthrene Orange R paste 


The cotton should of course be dyed first at as low a tempera- 
ture and alkalinity as possible. Obviously, considerably more care 
must be used in the application of heavy shades than for tints, 
and some loss of vat dyestuff may be expected. After the oxida- 
tion of the vat color, all traces of alkali should be removed from 
the goods by rinsing them in a dilute organic acid bath. The ace- 
tate silk can then be cross-dyed with Celanthrene dyestuffs, as 
given in Chapter XXII. The entire piece can be finished by soap- 
ing in the usual manner for the development of vat colors. 


Vat Dyes on Celanese-Cotton Unions 


The manufacturers of Celanese® have obtained patents upon a 
special method of applying certain vat dyes to cotton, as well as 
other materials, containing Celanese. This method involves the 
use of the alkali salts of phenolic bodies, such as sodium phenolate, 
naphtholate, resorcinate, cresolate, etc., and is based upon the fact 
that Celanese is not saponified by these compounds in the concen- 
tration required in the dyeing at temperatures below about 60° C. 
(140° F.). The process is protected by patent and may be used 
only on materials containing the Celanese brand of acetate silk. 
The following dyes have been recommended! * #°¢° for use by this 
method : 

Caldeon Red BN Fridan Scarlet R 


Indanthrene Red BK, RK, and 5GK ___sErridan Brilliant Scarlet B 
Anthrene Red BN Indanthrene Pink B 


Vote yY ES 


Indanthrene Orange 3R 
Anthrene Golden Orange RRT 
Indanthrene Golden Orange 3G 
Indanthrene Yellow RK and FFRK 
Cibanone Yellow R 

Hydron Yellow 2G 

Anthrene Jade Green 
Anthrene Green B 

Ponsol Green BN 

Caldeon Jade Green 

Algol Blue K 

Ponsol Blue 3G 

Duranthrene Blue 3GT 
Sulphanthrene Blue GR 
Indanthrene Blue 3G 

Hydron Blue G 


369 


Indanthrene Brilliant Violet 2R, 4R, 
RK, and 2BK 

Newport Violet 2R 

Ponsol Violet RRD 

Indanthrene Violet B and BN 

Duranthrene Red Violet 2RN 

Indanthrene Reddish-Violet RRK 

Anthrene Brown BB 

Indanthrene Brown R and 3R 

Algol Brown G and R 

Indanthrene Gray 3B, 6B, BTR, 
and RRH 

Ponsol Black B double 

Anthrene Black BB 

Indanthrene Black 2B 

Caledon Black B 


All of the above dyes leave Celanese practically unstained.* 
While Indanthrene Blues R and GC are not applicable by the 
phenolate method, good results are obtained with the methyl de- 
rivative formerly known as Algol Blue K and the Hydron Blues. 
In selecting vat dyes for use on the cotton of Celanese white or 
two-color effects, two factors are involved: (a) the dye must be 
applicable by the phenolate process, and (b) it must resist the 
acetate silk. Where a uniform color on both fibers is desired, D 
is of course of less importance. Undoubtedly other vat dyes than 
those mentioned in the list are useful by this method. Some Indi- 
goid vat dyes dye Celanese fairly well* but are not generally fast 
to rubbing. 

For economic reasons, sodium phenolate is the only one of the 
salts mentioned that is used in the commercial application of vat 
dyes by this method. This salt, especially in the presence of an 
amphoteric colloid such as glue, has much less hydrolyzing action 
on the acetate silk as well as on wool and silk, than a corresponding 
amount of caustic alkali. As in the application of the Caledon 
dyes to acetate silk unions, the cotton or viscose is dyed first and 
then the acetate silk cross-dyed with the S. R. A. dyes by the meth- 
ods previously given in Chapter X XI. 

In practice, the vat dye bath is prepared in exactly the same 
manner as for the application of the same dye to cotton or viscose 


370 ACETATE SILE 


alone, except that sodium phenolate is substituted for the caustic 
alkali. Or, if it is preferred, the vat dyes may be vatted in the 
usual manner with sodium hydroxide and then the vat neutralized 
with phenol or a related compound. However, this latter method 
requires very careful chemical control. As is well known, each 
individual vat dye differs from the others regarding the amount of 
sodium hydroxide and hydrosulfite required, and therefore only a 
general formula is possible here. 

Method No. ror: The Vat Dyes on Celanese-Cotton Umons. In 
preparing the “stock vat,” the vat dye paste, in quantity equivalent 
to 100 grams of the powder, is mixed with 10 liters of hot water 
of such a temperature as to give a final temperature of 50° C. 
(122° F.) in the stock vat; 3 kilos of sodium phenolate are added, 
and then about 300 grams of sodium hydrosulfite are sifted in 
while stirring well, until properly reduced. When the vat dye in 
powder form is used, the powder should first be pasted with 
Turkey-red oil before mixing it with the water. 

The 20 to 1 dye bath is prepared by adding for each 100 liters 
of bath, 60 grams of sodium phenolate, 15 grams of hydrosulfite, 
and 35 grams of glue, previously dissolved in water. An appro- 
priate quantity of the stock vat solution is then added. 

Where it is desired to prepare the dye bath directly without the 
use of a stock vat, the vat dye powder is pasted with a little 
Turkey-red oil and added directly to the 50° C. (122° F.) dye 
bath, which has previously been prepared by adding to each 100 
liters of solution, 1.5 kilos of sodium phenolate and 35 grams of 
glue, previously dissolved in water. The necessary quantity of 
sodium hydrosulfite is then dredged in and the bath gently stirred. 
After about 15 minutes, when the reduction is complete, the dyeing 
may proceed as usual. 

The goods are entered and dyed at 40 to 50° C. (104 to 122° 
F.). When properly conducted the Celanese should be practically 
unstained if a suitable vat dye has been selected; however, some 
vat dyes stain Celanese. After dyeing, the goods should be 
squeezed, oxidized, rinsed in soft water containing 0.2 grams of 
hydrosulfite per liter, and finally rinsed well in pure water. The 
material is then ready for cross-dyeing the acetate silk with the 


——— 


Wes DYES Byal 


S.R.A. dyes by the methods given in Chapter XXI. While the 
sodium phenolate vat dye solution does not readily attack Celanese, 
in dyeing it is advisable not to use a temperature above 60° C. 
(140° F.), instead of 75 or 80° C. as in the application of other 
dyes in a less alkaline solution. 

In using B-naphthol in the application of the vat dyes to the 
cotton of acetate silk-cotton unions, the following formulas have 
been suggested.® 


4 to 8 pints of 76° Tw. (1.380 sp. gr.) sodium hydroxide solution, 
1.75 to 3.5 pounds of B-naphthol, and 
1.5 to 4 pounds of hydrosulfite powder. 


Half of this caustic soda is used to dissolve the B-naphthol in 
the usual manner, by pasting and pouring on hot water. The dye- 
stuff is reduced in a separate vessel as follows: 


1 pound of vat dye in paste, 

2 gallons of water at 50 to 55° C. (120 to 130° F.), 
0.5 pint of 76° Tw. sodium hydroxide solution, and 

4 ounces of hydrosulfite powder. 


Any caustic soda or hydrosulfite remaining from the upper 
formula is added to the dye bath, followed by the B-naphthol 
solution, and then the reduced dyestuff solution, after 15 to 20 
minutes reduction. The dyed material is oxidized in the usual 
manner and then soaped at 70 to 80° C. (160 to 175° F.). The 
following dyestuffs have been recommended as applicable by this 


process. 
Duranthrene Yellow G Extra Duranthrene Brilliant Violet R 
Duranthrene Golden Orange Y and Duranthrene Green 2B 

2RT Duranthrene Blue GCD 
Duranthrene Red 5G and BN Duranthrene Olive R 
Duranthrene Red Violet 2RN Duranthrene Violet 2R 


As the following S.R.A. dyes are particularly fast to light, they 
are recommended? as very suitable for use on acetate silk unions 
containing vat-dyed cotton or viscose: 


S.R.A. Golden Yellow X S.R.A. Violet II 
S.R.A. Golden Orange I S.R.A. Blue III 
S.R.A. Golden Orange III S.R.A. Blue IV 


ouk.A, Red VII S.R.A. Black IV, developed with 
S.R.A. Heliotrope I BON 


372 ACET AY HoSiiis 


By this method a wide variety of very fast-to-light solid or con- 
trasting shades may be obtained on acetate silk-cotton or -viscose 
unions, using dyestuff combinations of which the following serve 
as examples: 


No. V-1: Solid Bright Saxe 
10% Ponsol Blue 3G paste and 
0.4% S.R.A. Blue IV paste. 


No. V-2: Solid Rose 
10% Anthrene Red BN paste, 
2% S.R.A. Red VII paste, and 
1% S.R.A. Golden Yellow X paste. 


No. V-3: Solid Violet 
5% Anthrene Violet 2R paste, 
1.5% S.R.A. Violet II paste, and 
0.8% S.R.A. Heliotrope I paste. 


No. V-4: Cotton Saxe, Celanese Orange 
10% Ponsol Blue 3G paste, 
10% S.R.A. Golden Orange III paste, and 
2%. S.R.A. Red VII paste. 


No. V-5: Cotton Green, Celanese Heliotrope 
5% Anthrene Jade Green paste, and 
2% S.R.A. Heliotrope paste. 


No. V-6: Cotton Rose, Celanese Blue 
10% Anthrene Red BN paste and 
2% S.R.A. Blue III paste. 


No. V-7: Cotton Brownish-Orange, Celanese Saxe 
10% Anthrene Golden Orange RRT se and 
2% S.R.A. Blue IV paste. 


No. V-8: Cotton Gray, Celanese Green 
10% Anthrene Black BB paste (after-treated with hypo- 
chlorite) 
1% S.R.A. Blue IV paste, and 
0.7% S.R.A. Golden Yellow X paste. 


No. V-9: Cotton Violet, Celanese Golden Orange 
5% Ponsol Violet RRD paste and 
2% S.R.A. Golden Orange I paste. 


No. V-10: Cotton Brown, Celanese Violet 
18% Anthrene Brown BB paste and 
2% S.R.A. Violet II paste. 


VAC DYES B73 


No. V-11 Cotton Saxe, Celanese Red 
7.5% Ponsol Blue 3G paste, 

2.5% S.R.A. Golden Orange III paste, and 
ogee kA. Ked VII paste. 

No. V-12: Cotton Green, Celanese Gold 
5% Anthrene Jade Green paste and 
2% S.R.A. Golden Orange III paste. 

No. V-13: Cotton Blue, Celanese Heliotrope 
10% Ponsol Blue 3G paste and 

1% S.R.A. Heliotrope I paste. 

No. V-14: Cotton Green, Celanese Red 
5% Anthrene Jade Green paste and 
Plone. Reo. Ked VIT paste. 

No. V-15: Cotton Green, Celanese Light Brown 
5% Anthrene Green Double B paste, 
2.5% S.R.A. Golden Orange I paste, and 
0.7% S.R.A. Violet II paste. 

No. V-16: Cotton Dark Blue, Celanese Cherry Red 
5% Sulfanthrene Blue BR paste and 
5% S.R.A. Red VII paste. 

No. V-17 Cotton Drab, Celanese Saxe 
1% Anthrene Brown BB paste and 
2% S.R.A. Blue IV paste. 

No. V-18: Cotton Violet, Celanese Gold 

5% Anthrene Violet 2R paste and 
10% S.R.A. Golden Yellow X paste. 


It is understood that this process is being widely used in Eng- 
land with most excellent results. 

Very probably some of the protective agents recommended for 
use in connection with the sulfur dyes on acetate silk-cotton dyes, 
such as sulfite cellulose liquor (Protectol), ammonium chloride or 
sulfate, glucose, cresolsulfonic acid, casein, etc., may also be of 
some value in the application of vat dyes to acetate silk. 

Also see British Patent No. 262,506. 


The New Soluble Vat Dyes 


The new “soluble vat” dyes, such as the Indigosols and Soledons 
offer interesting possibilities for use on acetate silk unions for 


374 ACETATE sik 


very fast shades on the cotton and wool. They are applied to 
cotton in a neutral dye bath, or to wool in about the same manner 
as the ordinary acid dye, and then oxidized on the fiber. A con- 
stantly increasing variety of colors are becoming available in this 
form, and while most of them do not have much affinity for acetate 
silk, they offer certain advantages for very fast prints, etc., on 
acetate silk-cotton or wool unions.® 


References 


1F. M. Stevenson, Dyer and Calico Printer 55, 86-8 (1926). 

*RGeDort Chemicals 25, No. 1, 22 (1926). 

= Coie. Mullin, Textile Colorist, January, February and September (1925). 

“G. H. Ellis, J. Soc. Dyers and Colourists 42, 184-6 (1926). 

5 American Cellulose and Chemical Co. “Celanese Dyeing Leaflet No. 5,” 
Ist Edition (April, 1926). 

ae Dyestuffs Corporation, “Dyeing and Printing Artificial Silk” 
(1926). 


CHAPTER XXX 


fie yeLOPHELD COLORS ON ACETATE SILK 
UNIONS 


As previously mentioned in connection with the production of 
the azoic or developed colors on acetate silk, most of the developed 
color components which are applicable to acetate silk alone are also 
applicable to acetate silk-cotton combinations, many of them leav- 
ing the cotton white, while others stain it more or less. Consider- 
able information along this line was given in connection with the 
discussion of the various brands of these products on acetate silk 
in Chapter XVI. In the same way, in dyeing the’cotton of acetate 
silk-cotton unions, such as hosiery, with developed colors, a num- 
ber of products are applicable, many of which do not dye the 
acetate silk; but quite a few of them stain it somewhat. 

In this connection, the difference in the order in which the de- 
veloped or azo dye components are applied to cotton and acetate 
silk should be noted. In applying the developed colors on cotton, 
the fiber is usually first padded in the naphthol bath and then the 
color developed in a second bath containing the diazotized amino 
base. In obtaining these colors on acetate silk, just the reverse of 
this order is used. The acetate silk is first treated with the amino 
base, for which it has a decided affinity. This is diazotized on 
the fiber and then developed in the naphthol or phenolic bath, the 
acetate silk having much less affinity for this latter component 
than for the amino compound. 

In dyeing the cotton of acetate silk with developed colors, where 
it is desired to leave the acetate silk unstained, only naphthol AS 
should be used in developing the cotton, as B-naphthol and the 
diamines have an affinity for the acetate silk and usually stain it 
pink or brownish. Method No. 102, covering the application of 
the Azoniles to the acetate silk of acetate silk-cotton unions, is an 
example of the procedure used in this class of work. The S.R.A. 
Diazo Solamines were at one time recommended for this work, 


375 


376 AGE TAT Hes lis 


especially for fast heavy shades on acetate silk-cotton hosiery ; but 
they have since been withdrawn from the market, except for — 
blacks, as the dispersol type of dyes are much easier to apply and 
in many instances are just as satisfactory with regard to fastness. 
While Method No. 102 covers the Azoniles, most of the other — 
brands of these dyes may be applied to acetate silk-cotton unions — 
by the process given in Methods No. 61 to No. 68-B in Chapter © 
XVI. ’ 
Method No. 102: The Azgoniles on Acetate Silk-Cotton Unions. 
The well-scoured and thoroughly wet-out union is entered into a~ 
40 to 1 dye bath containing the Azonile dye at 40 to 49° C. (105 to — 
120° F.). The temperature is raised to about 74° C. (165° F.) — 
for a half to three-quarters of an hour, and 10 to 20 per cent of — 
ammonium acetate is added. After dyeing, the goods are rinsed ~ 
in luke-warm water, diazotized as in Method No. 63-A, and de- ~ 
veloped with a suitable developer as in Method No. 63-B. The — 
cotton may be dyed in a fresh bath. Where the cotton is to be 
dyed with substantive dyes, it is usually best to dye the acetate ~ 
silk first according to a process similar to Method 102 and then ~ 
after diazotizing and developing, dye the cotton with such sub- — 
stantive dyes as do not stain acetate silk at 40 to 60° C. (104 to © 
140° F.), or at a maximum of 80° Co(176"aro: | 
It may be mentioned that Cellutyl Union Blacks R and G are 
mixtures prepared especially to give a solid black color on ace- — 
tate silk-cotton hoisery. They are diazotized and developed with q 
B-hydroxynaphthoic acid. The dye bath is prepared with 10 
per cent of dyestuff, 2 per cent of sodium carbonate, and 10 to 20 — 
per cent of sodium chloride. The goods are entered and the temp- — 
erature quickly raised to 80° C. (175° F.), for about an hour, — 
further additions of 30 per cent of salt being made. The ratio 
of dye bath to stock should be kept as low as possible. 
The dyed material is rinsed and diazotized for 20 minutes in a ~ 
cold bath containing 2.5 per cent of sodium nitrite and 7.5 per — 
cent of 32° Tw. hydrochloric acid. ; 
The material is then rinsed and developed for 30 minutes at — 
50° C. (120° F.) in a bath containing 5 per cent of B-hydroxy-_ 
naphthoic acid, acidulated with acetic acid. The goods are finally 


Pee OPED. COLORS Byars 


rinsed and soaped for 20 minutes at 50° C. (120° F.) in a bath 
containing 2 pounds of soap per 100 gallons of water. 

The S.R.A. Blacks III and IV really belong to the developed 
class as they are diazotized and developed on the fiber. In fact, the 
most satisfactory blacks for acetate silk available today belong to 
the developed class of dyes. While the Ionamines are a special class 
of dyes produced particularly for acetate silk, most of them really 
belong in the developed color class. In the discussion of the de- 
veloped colors in Chapter XVI, many references were made to 
developed colors on acetate silk similar to those used on cotton, 
such as Para-red, Primuline, etc. No doubt many of these proc- 
esses may be operated so as to dye both the acetate silk and the 
cotton. 

A. E. Hunter, in British Patent No. 191,120 of 1921, states 
that fabrics composed of viscose or other rayons in combination 
with acetate silk may be dyed in contrasting shades from a bath 
containing an excess of sodium carbonate or other suitable alkali, 
by using a dye containing one or more amino, alkylamino, or aryl- 
amino groups, 7.e., a dye capable of forming salts with acids, for 
coloring the acetate silk, and previously, simultaneously, or sub- 
sequently dyeing the viscose rayon another shade by means of 
a direct cotton dyestuff. 


CHAPTER X31 


THE IONAMINES ON ACETATE SILK COTTON 
UNIONS 


Tue fact that the Ionamines have no affinity for cotton or the 
older rayons renders them particularly useful in dyeing white — 
cotton or two-colored affects on acetate silk material. As they — 
may be applied in a dye bath slightly alkaline with sodium car- — 
bonate and are not affected by the presence of salt, these effects — 
as well as solid colors on acetate silk-cotton unions, may frequently — 
be obtained in one dye bath. Where two-colored effects are desired, 
it is usually best to cross-dye the cotton, in order to match the — 
shades with those of the sample. 

In this manner a deep solid black, suitable for hosiery, etc., is F 
obtained from a single dye bath containing a suitable diazotizable — 
cotton black and Ionamine A. Cellutyl Union Black R is probably — 
such a combination. The dyeing is carried out in a slightly alkaline — 
bath at 75° C. (167° F.) with the addition of 20 per cent of salt. 
The goods are then diazotized and developed with B-hydroxy- — 
naphthoic acid. Or the acetate silk may be dyed with the Iona- — 
mine A from a slightly acid bath, which is then rendered alkaline ~ 
with sodium carbonate ‘and the cotton dye added. 

As examples of the combinations possible, a bright orange 
shade on acetate silk and a blue shade on the cotton may be ob- — 
tained by means of Ionamine B and Chlorazol Sky Blue 2F, with- — 
out subsequent development. A blue shade on the acetate silk and — 
a bluish-red on the cotton may be obtained by dyeing with Primu-— 
line and Jonamine L in a slightly alkaline bath and developing with 
B-hydroxynaphthoic acid. A solid shade of red on acetate silk- 
cotton unions may be obtained directly with Ionamine Red KA and — 
Chlorazol Fast Red K. | 


378 


CHAPTER XXXII 


Pit DistERSOL DYES ON ACETATE SILK-COTTON 
UNIONS 


On account of the excellent fastness properties of many of the 
dispersol dyes, the large variety of colors available, their ease of 
application, and-the fact that they may be applied in the same dye 
bath with dyes of other classes, particularly the direct cotton dyes, 
to leave cotton unstained, they offer extremely interesting possibili- 
ties for, and are at present very widely used on, acetate silk-cotton 
unions, both for cotton-white and two-color effects. As mentioned 
in connection with the use of the vat dyes on the cotton of these 
unions, they offer a very simple and convenient method for obtain- 
ing shades on acetate silk of a fastness approaching that of the 
vat dyes on cotton. While some of the developed colors also have 
excellent and, in some cases, even superior fastness properties to 
some factors on acetate silk, their longer and more involved meth- 
ods of application frequently preclude their use. 

In cross-dyeing fabrics containing Celanese,’ where it is desired 
to leave the accompanying fibers (cotton or other rayons) un- 
stained, it is necessary to use a minimum amount of the dispersol 
dyestuff to bring the Celanese to shade. If deep shades are desired 
on the Celanese, it is best to add the dispersol dyestuff in portions, 
so that it will not flash onto the cotton or older rayon mechanically. 
The presence of from 0.5 to 1.5 gram of olive oil soap and 1 to 3 
cubic centimeters of Turkey-red oil or Celascour per liter of dye 
bath, is also an aid in leaving the other fibers unstained. The 
goods should be entered at about 71° C. (160° F.) and the tem- 
perature raised immediately to 76° C. (170° F.) at which they 
should be dyed. In this way clearer cotton whites are obtained 
than from a cold dye bath. 

If for any reason it is desired to enter the union into a cold dye 
bath, this may be done, and the temperature gradually raised to 
75° or 80° C. (167 or 176° F.). In either case the dye bath should 
not contain more than half of the direct cotton dye and preferably 


379 


380 ACETATE silts 


not all of the dispersol dyestuff, if white or contrasting cotton 
effects are desired. Where solid shades are being applied on both © 
fibers, less care can be given to the staining. If the dispersol dye 
was not all added to the bath at the start, it is best to complete the 
addition of this dyestuff before adding the rest of the direct cotton — 
dye, which is then added in portions as required, the salt being — 
added in the final stage to aid the exhaustion of the direct dye. 
The dyeing is usually complete in an hour or two at from 60 to 
80° C. (140 to 176° F.). After dyeing, the material should be 
given a light soaping for 10 minutes in a bath containing about — 
1.5 grams per liter of olive oil soap at 45° C. (113° F.). Slightly — 
stained whites may be cleared as directed in Chapter XXXV. 


Solid Shades on Acetate Silk-Cotton Unions 


The following formulas* will serve as examples of those used 
in obtaining solid shades on unions of Celanese with cotton or the 
older rayons: 


Formulae 
No. U-1: Light Gray 
1.0% S.R.A. Blue III paste, 
0.25% S.R.A. Golden Yellow IX paste, 
0.08% S.R.A. Orange I paste, 

0.3% -C.R. Cotton Fast Gray B and 
10.0%  Glauber’s salt. 
Enter cold and raise to 80° C. (176° F.) in 45 minutes. Dye 

at this temperature for 45 minutes. 


No. U-2: Pale Gold 
1.0% S.R.A. Golden Yellow IX paste, 
0.2% S.R.A. Heliotrope I paste, 
0.005% C.R. Cotton Fast Yellow B, and 
0.04% C.R. Cotton Fast Brown R. 
Enter cold and raise to 70° C. (158° F.) for about 2 hours. 


No. U-3: Fawn 
0.4% S.R.A. Blue III paste, 
0.65% S.R.A. Golden Yellow IX paste, 
0.04% S.R.A. Red I paste, 
0.05% C.R. Cotton Fast Brown R, 
0.04% Chlorazol Fast Yellow B, and 
5.0% Glauber’s salt. . 
Enter cold and raise to 75° C. (167° F.) in an hour and a half. 


Pee nolL DYES 381 


No. U-4: Tangarine 
3.5% S.R.A. Golden Yellow IX paste, 
Bio %o ok... ed I ‘paste, 
1.3% C.R. Cotton Fast Scarlet 4BS, 
1.3% C.R. Cotton Fast Yellow B, and 
10.0% Glauber’s salt. 
Enter cold and raise to 80° C. (176° F.) in 45 minutes, and 
hold at this temperature for 45 minutes. 


No. U-5: Apple Green 
0.95% S.R.A. Pure Yellow II paste, 
0.12% S.R.A. Blue IV paste, 
0.05% C.R. Cotton Fast Blue FF, 
0.125% C.R. Cotton Fast Yellow A, and 
10.0% Glauber’s salt. 
Enter cold and raise to 75° C. (167° F.) in an hour. 


No. U-6: Light Blue 
2.5% S.R.A. Blue IV paste, 
0.75% C.R. Cotton Blue FF, and 
10.0% Glauber’s salt. 
Enter cold and raise to 75° C. (167° F.) in an hour and a half. 


No. U-7: Dark Beaver 
1.4% S.R.A. Blue III paste, 
4.6% S.R.A. Golden Yellow VIII paste, 
Oavoe> ho. hed J paste, 
2.0% C.R. Cotton Fast Brown R, and 
0.2% C.R. Cotton Fast Blue FF. 
Enter cold and raise to 80° C. (176° F.) in 45 minutes and 
dye at this temperature for 45 minutes. 


No. U-8: Putty 
0.4% S.R.A. Blue III paste, 
0.5% S.R.A. Golden Yellow IX paste, 
0.06% S.R.A. Heliotrope I paste, 
0.015% C.R. Cotton Fast Gray B, 
0.008% C.R. Cotton Fast Brown R, 
0.001% C.R. Cotton Fast Yellow B, and 
5.0% Glauber’s salt. 


No. U-9: Flesh 
0.15% S.R.A. Orange I paste, 
0.0072% C.R. Cotton Fast Brown R, and 
0.004% C.R. Cotton Fast Scarlet 4BS. 


382 ACETATE Sikit 


No. U-10: Mushroom 
0.3% S.R.A. Blue III paste, 
0.1% S.R.A. Golden Yellow IX paste, 
0.01% S.R.A. Red I paste, 
0.01% C.R. Cotton Fast Gray B, 
0.003% C.R. Cotton Fast Yellow B, 
0.001% C.R. Cotton Chlorazol Fast Red BL, and 
5.0% Glauber’s salt. 


No. U-11: Nigger 
15.0% S.R.A. Blue III paste, 
10.0% S.R.A. Golden Yellow VIII paste, 
0.5% S.R.A. Red I paste, 
4.0% C.R. Cotton Fast Brown R, 
0.3% C.R. Cotton Fast Blue FFB, and 
20.0% Glauber’s salt. 


No. U-12: Scarlet 
5.0% S.R.A. Red I paste, 
1.25% C.R. Cotton Fast Scarlet 4BS, and 
15.0% Glauber’s salt. 
Enter cold and dye at 75° C. (167° F.) for an hour and a 
half. 


No. U-13: Maize 
3.2% S.R.A. Golden Yellow IX paste, 
0.12 S.R.A. Orange I paste, 
0.5% C.R. Cotton Fast Yellow B, 
0.16% C.R. Cotton Fast Orange 5R, and 
0.04% C.R. Cotton Fast Blue FFB. 


No. U-14: Navy 
25.0% S.R.A. Blue III paste, 
4.0% S.R.A. Golden Yellow IX paste, 
4.0% S.R.A. Orange IT paste, 
2.5% C.R. Cotton Diazo Black BH, and 
20.0% Glauber’s salt. 


No. U-15: Light Brown 
5.0% S.R.A. Orange IIT paste, 
2.5% S.R.A. Golden Yellow IX paste, 
0.9% S.R.A. Heliotrope I paste, 
0.45% C.R. Cotton Fast Brown R, and 
10.0% Glauber’s salt. 


Dist EP ROOL DYES 383 


No. U-16: Black 
0.4% S.R.A. Blue IV paste, 
0.2% S.R.A. Golden Yellow III paste, 
6.0% C.R. Cotton Fast Black B, 
30.0% Glauber’s salt, 
1 gram per liter of olive oil soap, and 
2 cubic centimeters per liter of Turkey-red oil. 


Solid Black Shades 


In applying a solid black on acetate silk-cotton unions by means 
of dispersol dyes in combination with a direct cotton dyes,’ such 
as Diazo Fast Black, the usual cross-dyeing procedure for the 
application of dispersol dyes should be reversed. In other words, 
the cotton should be dyed first with the direct dye, and then the 
acetate silk with the dispersol black (for instance, Celatene Black), 
in a separate bath. If the usual method of dyeing the acetate silk 
first is followed, the Celatene Black does not always go on well and 
the resulting shade may be brownish. 


Two-Color Effects on Acetate Silk-Cotton Unions 


Two-color effects on acetate silk-cotton unions are obtained in 
the same manner and by the same processes as the solid color 
effects, except that more care must be exercised to avoid staining 
the accompanying fiber. For this reason it is sometimes advisable 
to use a two-bath process, dyeing the acetate sillx with the dispersol 
dye first, and then dyeing the cotton in a separate bath. Another 
method, which corresponds more closely to this two-bath method 
and frequently gives even better results, is first to dye the acetate 
silk in a dispersol-dye bath and, when the exhaustion is practically 
complete, to start adding the direct dye, leaving the salt addition 
until near the last. In this process there is no danger of stripping 
some of the dispersol dye during the application of the direct dye, 
and when properly handled, excellent results are obtained. The 
following formulae are of interest for two-color effects on cotton 
or rayon-acetate silk unions. 


384 ACH PATE slit 


Formulae 


No. U-17: Celanese Flame, Cotton or Older Rayon Gray 
2.0% S.R.A. Orange I paste, 
0.5% S.R.A. Pure Yellow I paste, | 
0.3% C.R. Chlorazol Fast Gray or C.R. Cotton Fast Gray 
B, and ; 
10.0% Sodium chloride or sulfate. 


No. U-18: Celanese Deep Saxe, Cotton Gray 
5.0% S.R.A. Blue II paste or 7.0% S.R.A. Blue IV paste, 
0.3% C.R. Chlorazol Fast Gray or C.R. Cotton Fast Gray — 
B, and . 
10.0% of sodium chloride or sulfate. 


No. U-19: Celanese Crimson, Cotton Saxe 
6.0% S.R.A. Red III paste, 

1.2% S.R.A. Red V paste, j 

1.0% C.R. Chlorazol Fast Blue 2B or C.R. Cotton Blue 

2B, and 4 

20.0% of sodium chloride or sulfate. 


No. U-20: Celanese Royal, Cotton Rose 
7.5% S.R.A. Blue III paste or 8.0% S.R.A. Blue I paste, 
0.25% C.R. Chlorazol Fast Red K or C.R. Cotton Fast Red — 
BL, and 
10.0% of sodium chloride or sulfate. 


No. U-21: Celanese Cherry, Cotton Green 
1.59 3.RWA. Rede) paste, 
2.0% C.R. Cotton Fast Blue 4GL or 2.5% C.R. Chlora-— 
0.7% C.R. Cotton Fast Yellow B zol Fast Green, and — 

20.0% of sodium chloride or sulfate. | 


No. U-22: Celanese Violet, Cotton Green 
5.0% S.R.A. Heliotrope I paste, 
2.5% S.R.A. Fast Blue III paste, q 
2.5% C.R. Cotton Fast Green 2G or C.R. Chiseel Fast — 

Green, and 3 
20.0% of sodium chloride or sulfate. 


No. U-23: Celanese Brick, Cotton Gray 
0.25% S.R.A. Orange I paste, 
0.25% S.R.A. Red I paste, 

0.8% C.R. Chlorazol Fast Gray or C.R. Cotton Fast Gray 
ib eand 
10.0% of sedium chloride or sulfate. 


ieee kRSOL DYES 385 


No. U-24: Celanese Lemon, Cotton Amethyst 
2.5% S.R.A. Yellow III paste or 1.0% Pure Yellow I paste, 
0.2% C.R. Chlorazol Fast Blue 2B or C.R. Cotton Blue 2B, 
0.8% C.R. Chlorazol Violet R or C.R. Cotton Violet BBR, 
and 
10.0 or 20% of sodium chloride or sulfate. 


No. U-25: Celanese Bronze, Cotton Green 
3.0% S.R.A. Golden Yellow VIII paste 
0.5% S.R.A. Red I paste, 

2.5% S.R.A. Blue III paste 


or 

3.0% S.R.A. Pure Yellow I paste, 
0.5% S.R.A. Orange I paste, 
2.5% S.R.A. Blue I paste, and 


2.0% C.R. Cotton Fast Blue 4GL, 
0.7% C.R. Cotton Yellow B, 


or 
2.5% C.R. Chlorazol Fast Green, and 
20.0% of sodium chloride or sulfate. 


No. U-26: Celanese Orchid, Cotton Sky Blue 
1.0% S.R.A. Heliotrope I paste or Red V paste, 
0.25% C.R. Chicrazol Sky Blue FF or C.R. Cotton Blue 
FF, and 
10.0% of sodium chloride or sulfate. 


No. U-2%: Celanese Reseda, Cotton Brown 
4.0% S.R.A. Golden Yellow VIII paste, 
2.0% S.R.A. Blue IV paste, 


or 
4.0% S.R.A. Pure Yellow I paste, 
bCge oA. Blue I] paste; 
2.5% C.R. Cotton Fast Brown R or C.R. Chlorazol Fast 
Brown No. 1, and 
20.0% of sodium chloride or sulfate. 


Acetate Silk-Cotton or Rayon Hosiery or Kut Unions 
The dyeing of hosiery or other knit goods containing acetate 
silk in combination with cotton or the older rayons frequently 
presents a special problem, particularly where there are seams to 
be penetrated. In case of difficulty in penetrating these seams, a 
steeping operation is of great benefit in leveling, etc., especially in 
machine dyeing. It also aids in penetrating the cotton. at the 


386 ACETATE Stes 


restricted dyeing temperature of 80° C. (176° F.). The steep 
may be either cold or warm, either over-night or for a shorter 
period. Frequently the goods are simply allowed to remain in the 
scouring bath overnight, with excellent results. : 

In applying the S.R.A. dyes to Celanese-cotton hosiery, the 
Celanese manufacturers recommend that it be scoured by Method: 
No. 6 and then allowed to remain in the scouring bath overnight. 
For the lighter shades, the union may be bleached as in Method 
No. 15 and antichlored as in Method No. 18. Small lots may be’ 
dyed by hand, but larger lots may be dyed either in a revolving 
drum or in the paddle machine. Copper or monel metal is advis-— 
able. The same general directions regarding the addition of dye- 
stuff to the dye bath, etc., are followed as in dyeing other Celanese 
unions. 3 7 

Dort! states that in dyeing Celanese-cotton hosiery, in order to 
insure proper penetration of the cotton tops, toes, and heels at a_ 
temperature of 82° C. (180° F.), direct cotton dyes should be 
selected which have the very best penetrating and leveling powers. 
These should be applied with as much as 10 cubic centimeters of 
Celascour per liter of dye bath. Where it is necessary to boil the 
cotton dyes onto the cotton, the method covered by British Patent 
No. 246,879 should be used. He recommends a 20 to 1 dye bath 
but states that satisfactory results have been obtained with a 10 to” 
1 bath. The following are examples of formulae which have given 
good results on Celanese-cotton or rayon unions: 


Formulae 


No. HU-1: Beige 

Or(-7o 3 RA, Blue lo paste; 

0.5 S.R.A. Orange I paste, 

0.9% S.R.A. Pure Yellow I paste, 

0.125% C.R. Chlorazol Brown PB, 

0.1% C.R. Chlorazol Orange AG, 

0.01% C.R. Chlorazol Fast Orange R, and 

10 % of salt. 

Enter cold and dye at 75° C. (167° F.) for one and a half 
hours. | 


a See Chapter XXV. 


Psi Rol DYES 


No. HU-2: Putty 
1.25% S.R.A. Blue I paste, 
0.1% S.R.A. Orange I paste, 
1.0% S.R.A. Pure Yellow paste, 
0.15% C.R. Chlorazol Drab RH, 
0.025% C.R. Chlorazol Yellow G, and 
10 % of salt. 
Dye as in Formula No. HU-1. 


No. HU-3: Light Gray 
1.25% S.R.A. Blue I paste, 
0.3% S.R.A. Orange I paste, 
0.25% S.R.A. Pure Yellow paste, 
0.1% C.R. Chlorazol Fast Gray, and 
5% of salt. 


387 


Enter cold and dye at 65° C. (149° F.) for one and a half 


hours. 


No. HU-4: Mole 
6% S.R.A. Blue I paste, 
1% S.R.A. Orange I paste, 
2% S.R.A. Pure Yellow I paste, 
0.5% C.R. Chlorazol Drab RH, 
0.35% C.R. Chlorazol Brown RD, and 
15% of salt. 
Dye as in Formula No. HU-1. 


No. HU-5: Flame 
0.2% S.R.A. Blue I paste, 
3.5% S.R.A. Orange I paste, 
1.0% S.R.A. Red III paste, 
1.2% Chlorazol Brown RK, 
0.1% Chlorazol Brown M, and 
10 % of salt. 
Dye as in Formula No. HU-1. 


No. HU-6: Tan 
4% S.R.A. Blue I paste, 
1.1% S.R.A. Orange I paste, 
1.5% S.R.A. Pure Yellow I paste, 
0.3% C.R. Chlorazol Drab RH, 
0.25% Chlorazol Brown RK, and 
10% of salt. 
Dye as in Formula No. HU-1. 


388 ACETATE SILKE 


No. HU-7: Dark Brown 

10% S.R.A. Blue I paste, F 
2% S.R.A. Orange I paste, 
2% S.R.A. Pure Yellow I paste, 

1.2% Chlorazol Brown RD, 

0.15% Chlorazol Brown RK, and 

20% of salt. 

Dye as in Formula No. HU-1. 


No. HU-8: Silver 
0.3% S.R.A. Blue III paste, 
0.08% S.R.A. Golden Yellow VIII paste, and 
0.03% S.R.A. Heliotrope I paste, 
0.1% Chloramine Fast Gray R, and 
5.0% Glauber’s salt. 


No. HU-9: Maize 
3.2% S.R.A. Golden Yellow IX paste, 
0.12% S.R.A. Orange I paste, 
1.5% C.R. Cotton Fast Yellow B, 
0.16% C.R. Cotton Fast Orange 5R, and 
0.04% C.R. Cotton Fast Blue FFB. 


No. HU-10: Nude 
0.075% S.R.A. Golden Yellow IX paste, 
0.005% S.R.A. Orange I paste, 
0.005% C.R. Cotton Fast Orange 5R, 
0.005% C.R. Cotton Fast Scarlet 4BS, and 
20.0% Glauber’s salt. 


No. HU-11: Stone 
0.3% S.R.A. Blue III paste, 
0.8% S.R.A. Golden Yellow IX paste, 
0.2% S.R.A. Heliotrope I paste, 
0.06% C.R. Cotton Fast Brown R, 
0.01% C.R. Cotton Fast Gray B, and 
5.0% Glauber’s salt. 


No. HU-12: Putty 
0.4% S.R.A. Blue III paste, 
0.5% S.R.A. Golden Yellow IX paste, 
0.06% S.R.A. Heliotrope I paste, 
0.015% C.R. Cotton Fast Gray B, 
0.008% C.R. Cotton Fast Brown R, 
0.001% C.R. Cotton Yellow B, and 
5.0% Glauber’s salt. 


PisPERSOL DYES 389 


No. HU-13: Flesh 
0.15% S.R.A. Orange I paste, 
0.0072% C.R. Cotton Fast Brown R, and 
0.0004% C.R. Cotton Fast Scarlet. 


No. HU-14: Mushroom 
0.3% S.R.A. Blue III paste, 
0.1% S.R.A. Golden Yellow IX paste, 
0.01 S.R.A. Red I paste, 
0.01% C.R. Cotton Fast Gray B, 
0.003% C.R. Cotton Fast Yellow B, 
0.001% C.R. Chlorazol Fast Red BL, and 
5.0% Glauber’s salt. 


No. HU-15: Cinnamon 
0.6% S.R.A. Blue IIT paste, 
6.0% S.R.A. Golden Yellow IX paste, 
0.9% S.R.A. Heliotrope I paste, 
0.45% C.R. Cotton Fast Brown R, and 
10.0% Glauber’s salt. 
No. HU-16: Nigger 
15.0% S.R.A. Blue III paste, 
10.0% S.R.A. Golden Yellow VIII paste, 
0.5% S.R.A. Red I paste, 
4.0% C.R. Cotton Fast Brown R, 
0.3% C.R. Cotton Fast Blue FFB, and 
20.0% Glauber’s salt. 
No. HU-17: Navy 
25.0% S.R.A. Blue III paste, 
4.0% S.R.A. Golden Yellow IX paste, 
4.0% S.R.A. Orange II paste, 
2.5% C.R. Cotton Diazo Black BH, and 
20.0% Glauber’s salt. 


Black on Celanese-Cotton Hosiery and Knit Goods 


It is now recommended? to use Method No. 103 for a solid black 
on Celanese-cotton hosiery and knit goods. When the Sta; 
Fast Black Developer HY Special is used it is no more difficult to 
obtain a fast black on these mixed goods than to obtain a developed 
black upon cotton alone. The only difference between this process 
and that generally used for cotton is that the acidified developing 
bath is used warm, instead of cold. ; 


390 ACETATE SUAS 


Method No. 103: Developed Black on 50-50 Celanese and Cot- 
ton Knit Goods. Enter the goods into a 20 to 1 dye bath at 45° 
C. (113° F.) containing 10 per cent of S.R.A. Black IV and 4 
to 6 per cent of Chlorazol Black LF or Diamine Fast Black C 
conc. Raise the temperature during an hour or an hour and a half 
to 75° C. (167° F.), adding 40 per cent of sodium chloride in 
portions. Rinse the goods before diazotizing. 

Method No. 103-A: Diazotizing Black on Knit Goods. Diazotize 
the goods in a 20 to 1 bath for one hour with 5 per cent of 98 
per cent sodium nitrite and 14 per cent of 28 per cent hydrochloric 
acid. . 

Method No. 103-B: Developing Black on Kmit Goods. Dissolve 
1 to 1.5 per cent of sodium hydroxide, on the weight of the fiber, 
in water and work 2 or 3 per cent of S.R.A. Black Developer HY 
Special into a paste with it, adding hot water to complete the solu- 
tion. Dissolve 5 per cent of glue, also on the weight of the goods, 
in water and add it to the 25 to 1 developing bath; then add the 
dissolved developer to the bath. Lastly add 5 per cent of 80 per 
cent formic acid to the bath and stir well. Enter the goods and 
raise the temperature to 60° C. (140° F.) during an hour. When 
the development is complete, rinse in water at about 45° C. (113° 
F.), then in cold water, and finally soap well in a bath containing 
0.5 to 1 gram per liter of olive oil soap. Then rinse well again. 


The Celatene Dyes on Acetate Silk-Cotton Unions 


The Celatene dyes resemble the S.R.A. dyes in many ways and 
are applied by the same general methods to acetate silk-cotton 
unions. While most direct dyes may be applied to cotton in the 
same dye bath and concurrently with the application of the Cela- 
tene dyes to the acetate silk, in order to obtain colors of similar 
fastness on both fibers, it is desirable to use vat dyes on the cotton, 
as described in Chapter XXIX. This of course necessitates the 
use of the two dye baths. The Caledon vat dyes have proven par- 
ticularly useful for this purpose, but many of the vat dyes men- 
tioned in the list for vat dyes on Celanese-cotton unions may also 
be used in the same way. Some Celatenes stain cotton slightly, but 
it may be cleared by the methods given under Clearing Unions, 
Chapter XXXV. 


Piste eRoSOL DYES 391 


The Duranol and Dispersol dyes have no affinity for cotton, the 
older rayons or other vegetable fibers and may therefore be used 
on acetate silk-cotton unions to excellent advantage by the usual 
methods, such as those given in Chapter XXII, with the precau- 
tions mentioned in the foregoing paragraphs. 

The Direct Azonines do not appreciably stain cotton and may 
readily be used to obtain two-color effects on acetate silk-cotton 
unions. As usual in dyeing such unions, the acetate silk should be 
dyed first and then the cotton dyed at not over 40 to 60° C. (105 
to 120° F.) with the addition of Glauber’s salt, but without the 
addition of sodium carbonate, using such dyes as do not stain the 
acetate silk. 

The “Extra Pastes for Acetate Silk” of the Badische Company 
are also applicable to acetate silk-cotton unions. When applied in 
light shades, the cotton usually remains unstained, but heavier 
dyeings generally tint the cotton somewhat. They may be applied 
in the same dye bath with most of the direct cotton dyes. For 
two-colored effects upon acetate silk-cotton unions by the single 
bath method, 5 to 20 per cent of calcined Glauber’s salt should be 
added to the dye bath as given in Method No. 81. All soda or 
other alkalines should be strictly avoided. Solid shades are dyed 
in the same manner. Care should be taken that both fibers are 
alike in tone, but the acetate silk rather on the light side of the 
cotton. . 

The Celanthrene dyes can be used upon cotton-acetate silk 
unions for either cotton-white or two-colored effects. Their fast- 
ness to light suggests the use of vat dyestuffs upon the accom- 
panying cotton, as mentioned in Chapter XXIX. Where cotton- 
white effects are desired, the Celanthrenes are applied as in Chap- 
ter XXII. In some cases it may be necessary to clear the cotton 
by means of a light soaping, as in Method No. 112. 


References 


1R. G. Dort, American Dyestuff Reporter 15, 258-66 (1926). 

2W.M. Todd, Dyer and Calico Printer 55, 126 (1926). 

8 American Cellulose and Chemical Co., “Practical Notes on Dyeing 
Celanese.” Celanese Dyeing Leaflet No. 2, 3rd Edition. 

*R. G. Dort, Chemicals 25, No. 1, 22-6 (1926). 


CHAPTER XXXIII 


DIRECT COTTON DYES WHICH LEAVE ACETATE 
SILK WHITE 


In any discussion of the dyeing of combinations of acetate silk 
with other fibers, the study of the direct cotton dyes which leave 
acetate silk either white or only very slightly stained is of the 
utmost importance. Whether the acetate silk is to be present as 
white, or with undyed effects, dyed in a contrasting, or even in a 
similar shade, much better results are obtained by using dyestuffs 


for each fiber which give a minimum of staining on the accom- — 


panying fibers, due to the better control of the resulting shades. 


$ 


| 
: 
| 


ae Pe 


However, it is of course obvious that the direct cotton dyes which ~ 
stain or dye acetate silk may have a certain field of usefulness for — 
solid color effects on acetate silk-cotton or rayon unions, but 
usually much better and brighter shades are obtained on the acetate — 


silk, by the use of the special dyes for this fiber. 
Certain direct browns, reds, and greens have a particular in- 


a. S 


clination to stain acetate silk slightly, and in applying these prod-— 


ucts, or in fact in dyeing any unions of two or more fibers where it 
is desired to leave one fiber white, it is always best to add the dye 


to the bath in small quantities at the start, and only add more dye ~ 
to the bath as the liquor is exhausted by the fiber to be dyed. In ~ 
the case of direct cotton dyes, the salt should be added only after 2 
the bath has been brought up to temperature. In this way the 
fiber to be dyed, which naturally should have the greatest affinity | 
of the two fibers for the dyes used, is dyed with a minimum of dye-— 
stuff and no excess of dye should be allowed in the bath. The | 
presence of dyeing assistants and leveling agents, as well as the 
use of a long dye bath, all assist in keeping the one fiber white. 
Sodium chloride is frequently preferable, in place of the sulfate, — 
to aid exhaustion. Method No. 105 has been recommended for 


white acetate silk effects. 


Method No. 105: White Acetate Silk Effects in Acetate Silk- | 
Colored Cotton Unions. The direct cotton dye should be applied in - 


392 


Diner COLTON DYES RESULTS 393 


a 20, or better yet, 30 to 1 dye bath, containing the necessary amount 
of dyestuff and 20 to 30 per cent of sodium chloride or sulfate. The 
thoroughly wet-out goods are entered and worked for an hour at 
71 to 76° C. (160 to 170° F.). For blacks it is advisable to raise 
the temperature to 80 to 85° C. (175 to 185° F.) and use about 40 
per cent of salt to insure penetration. Alkaline baths should be 
avoided, and the dyed goods should be rinsed well and soaped to 
clear the acetate silk. This is followed by another thorough rins- 
ing. Turkey-red oil will aid penetration and leveling, and is there- 
fore especially useful for light shades. 

From our study of the chemical composition and properties of 
the different brands of acetate silk, it is obvious that the staining 
properties of the various direct cotton, as well as any other class 
of dyestuffs, may vary somewhat on the different products. While 
most of the information concerning the staining properties of the 
various dyes on acetate silk is rather general, it may be assumed 
that in most instances it has particular reference to Celanese. The 
Newport Chemical Works has made a more detailed study of the 
matter in connection with their products, and the following is a 
summary of their results. As a rule it may be assumed that the 
staining properties of Rhodiaseta, and the other brands of acetate 
silk more closely approximate those of Celanese than Lustron. 

Direct cotton dyes leaving Celanese white: 


Yellow 
Newport Chrysophenine Extra 
Newport Direct Yellow G 
Newport Direct Fast Yellow NN 
Newport Direct Pure Yellow S 


Orange 
Newport Direct Orange 2RG and 
vara 


Newport Direct Fast Orange RS 


Blue 
Newport Direct Sky Blue, and the 
FF brand 
Newport Direct Fast Blue 4GL, 
SFF, and SFR 
Newport Benzo Azurine G Extra 
Newport Direct Blue BH Extra 
conc., 2B conc., BX, 3BX, and RS 
Newport Direct Brilliant Blue G 


Red 
Newport Direct Fast Scarlet G, 
4BA, and 8BA 
Baca Direct Fast Red 8BL, and 


Newport Benzo Purpurine 4B conc., 
and 10B cone. 
Newport Direct Garnet R 


Pink 
Newport Direct Pink 12B Special, 
and EBN 
Newport Direct Pink 2B 


Brown 
Newport Direct Brown CR, GRN, 
and N3G 
Newport Direct Fast Brown M, BT, 
and T2G 
Newport Union Brown No. 17881 


394 


Direct cotton dyes leaving Lustron white: 


Black 
Newport Direct Fast Black WCT 


Violet 
Newport Direct Violet N 


Gray 
Newport Neutral Gray GG 


Yellow 
Newport Direct Pure Yellow S 
Newport Chrysophenine Extra 
Newport Direct Fast Yellow NN 
Newport Direct Yellow G 


Orange 
Newport Direct Orange 2RG, and R 
Newport Direct Fast Orange RS 
Blue 


Newport Direct Blue BH Ex conc., 
2B conc., 3BX, and RS 
Newport Direct Fast Blue SFF, 


ACETATE SILK 


2GL, 4GL, FF, and SFR 
Newport Direct Sky Blue 


Red 
Newport Direct Fast Scarlet G, 
-4BA, 4BS, and 8BA 
Newport Benzo Purpurine 4B conc., 
and 10B conc. 2 
Newport Direct Garnet R 
Newport Direct Fast Red F 


Pink 
Newport Direct Pink 2B . 
Newport Direct Fast Pink E2GN, 
12B special, and EB Extra . 


Brown 
Newport Direct Fast Brown BT 
Newport Direct Bown XR = 
Violet 
Newport Direct Violet N 


Direct Cotton Dyes Which Leave Lustron Effects Slightly | 


Stained : 
Orange 
Newport Direct Orange 2R 


Newport Direct Brown GXR 
Newport Direct Brown RXN 


Direct Cotton Dyes Which Leave Lustron Effects Badly 


Stained: 


Black 
Newport Direct Black EG Extra 


Brown 


Newport Direct Brown RG 
Newport Direct Fast Brown M 


: 
: 
: 


Blue . 
Newport Direct Fast Blue RW 


Violet 


Newport Direct Brilliant Violet R 
conc, 


Cotton Dyes Leaving Rhodiaseta white: 


Naphthamine Yellow BN and GN 

Chrysophenine GK 

abe Se = Orange 2R (CI. No. 
621 

epee Fast Scarlet E4B and 

Naphthamine Fast Red R 

Cotton Fast Violet B 


Naphthamine Blue 2B and 12B 
Naphthamine Black CE and WR 
Naphthamine Fast Green G 
Naphthamine Brown H and T 
Naphthamine Fast Gray B 
Diazogene Black 53861 developed 
with resorcinol 


Pree COLrON DYES RESULTS 


a99 


The American Cellulose and Chemical Company gives the fol- 
lowing list of direct cotton dyes which leave Celanese white and 
which have good fastness to light and washing: 


Black and Grays 


Chloramine Fast Gray R (Sandoz) 
C.R, Cotton Black B (Celanese) 
C.R. Cotton Black FWW (Cela- 


nese) 
Direct Black A-68396 (National) 


Blue 


Chlorantine Fast Blue 8GL (Ciba) 

Chlorantine Fast Blue GLM (Ciba) 

Chlorantine Fast Blue RL (Ciba) 

C.R. Cotton Fast Blue FFB (Cela- 
nese) 

C.R. Dianol Fast Blue 2BM (BDC 
and DCA) 

Pontamine Fast Blue 2GL (Du 
Pont) 

Pontamine Fast Blue 4GL (Du 
Pont) 

Solantine Blue 4GL (National) 

Solantine Blue RL (National) 


Brown 


C.R. Cotton Fast Brown R (Cela- 
nese) 
Erie Fast Brown 2RB (National) 


Green 
Chlorantine Fast Green BL (Ciba) 


Orange 
Pontamine Fast Orange EG (Du 
Pont) 
Solantine Orange A (National) 


Red and Pink 


Chlorantine Fast Bordeaux BL 
(Ciba) 

Chlorantine Fast Rubine RL’ (Ciba) 

C.R. Cotton Fast Red BL (Cela- 
nese) 

Direct Fast Ereca 2BW (Ciba) 

Solantine Red 8BLM (National) 


Violet 


Direct Fast Heliotrope BL (Na- 
tional) 
Solantine Violet R (National) 


Yellow 
C.R. Cotton Fast Yellow B (Cela- 


nese) 
Erie Fast Yellow WB (National) 
Fast Yellow NN (Newport) 
Pontamine Fast Yellow NN (Du 
Pont) 
Pontamine Yellow CH (Du Pont) 


The same authority also gives the following list of direct 
cotton dyes which leave Celanese white and which have good fast- 
ness to light (those marked L) or washing (W) but not always 


to both: 


Black and Gray 


C.R. Cotton Diazo Black BH (L) 
(Celanese) 

Diazine Black BO (L) (National) 

Diazo Black BH extra conc. (L) 
(Newport) 

Pontamine Fast Gray B (L) (Du 
Pont) 


Blue 
Chloramine Fast Blue BS (L) 
(Sandoz) 
Direct Fast Blue SFR (L) (New- 
port) 


Niagara Blue 3B (W) (National) 

Niagara Blue NR (W) (National) 

Pontamine Navy Blue DB (W) 
(Du Pont) 


396 


Brown 
C.R. Chlorazol Fast Brown RD 
(W) (BDC & DCA) 
Direct Fast Brown BT (W) (New- 


port) 
Erie Brown CN (W) (National) 


Orange 
Chloramine Fast Orange SE (L) 
(Sandoz) 
C.R. Dianol Fast Orange 2G (W) 
(BDC & DCA) 
Direct Orange 2R (W) (Newport) 


Red and Pink 


C.R! Cotton Fast Pink» 2B (L) 
(Celanese) 

C.R. Cotton Fast Scarlet 4BS (W) 
(Celanese) 

C.R. Dianol Fast Red K (L) (BDC 
& DCA) 

C.R. Dianol Scarlet 4BS (W) (BDC 
& DCA 


CA) 
Direct Fast Pink 2B (W) (New- 
port) 
Direct Fast Red 8BL (L) (New- 
port) 
Direct Fast Scarlet G (L) (New- 


port 
Direct Fast Scarlet 4BA (W) 
(Newport) 


ACETATE SIEE 


Direct Fast Scarlet 8BA (W) 
(Newport) 

Erie Scarlet 8BA (W) (National) 

Pontamine Fast Pink G (W) (Du 
Pont) 

Pontamine Fast Scarlet 4BS (L) 
(Du Pont) 


Violet 


Chloramine Fast Violet B (L) 
(Sandoz) 

Chlorantine Fast Violet 4BL (L) 
(Ciba) 

C.R. Cotton Fast Violet BL (L) 
(Celanese) 


Yellow 


C.R. Cotton Fast Yellow A (W) 
(Celanese) 

Erie Yellow 2RF (W) (National) 

Erie Yellow Y (L) (National) 

Pontamine Yellow GR (W) (Du 
Pont) 

Pontamine Yellow SXG (W) (Du 
Pont) 

Pontamine Yellow SXR (W) (Du 
Pont) 

Solantine Yellow A (W) (National) 

C.R. Dianol.~ Fast “Yellow Aw 
(W) (BDC & DCA) 


From the same source, direct cotton dyes which leave Celanese 
white and have fair fastness to light and washing: 


Black and Gray 
Chlorantine Fast Gray BLN (Ciba) 
Chlorantine Fast Gray GLN (Ciba) 
Chloramine Fast Gray B (Sandoz) 
C.R. Cotton Black 3G (Celanese) 
Diazine Black RS (Newport) 
Pontamine Fast Black CW (Du 


Pont) 
Diazo Black HEX (National) 


Blue 


Chlorantine Fast Blue 2GL (Ciba) 

C.R. Cotton Blue FF (Celanese) 

C.R. Cotton Blue 2B (Celanese) 

C.R. Cotton Fast Blue 4GL (Cela- 
nese) 

C.R. Cotton Sky Blue (Celanese) 

C.R. Dianol Fast Blue 4GL (BDC 
& DCA) 


C.R. Dianol Sky Blue 5BX (BDC & 
DCA) 
Diazo Fast Blue 6GW (Ciba) 
Direct Fast Blue SFF (Newport) 
Direct Sky Blue FF (Newport) 
Fast Blue 4GL (Newport). 
Niagara Blue DB (National) 
Niagara Blue 2B (National) 
Niagara Blue HW (National) 
Niagara Sky Blue (National) 
Niagara Sky Blue 6B (National) 
Pontamine Blue BBF (Du Pont) 
Pontamine Blue CLG (Du Pont) 
Pontamine Blue GH conc. (Du 
Pont) 
Pontamine Fast Blue SLN (Du 
Pont) 
Pontamine Sky Blue 5BX (Du 
Pont) 


} 
‘ 


Pret COLTON DYES RESULTS 


Brown 


C.R. Chlorazol Brown B Extra 
(BDC & DCA) 

C.R. Chlorazol Fast Brown B Extra 
(BDC. & DCA) 

C.R. Chlorazol Fast Brown RK 
(BDC & DCA) 

Erie Catechine 3G (National) 


Green 
C.R. Cotton Green 2G (Celanese) 


Orange 

Chlorantine Fast Orange 2RL 

(Ciba) 

C.R. Cotton Fast Orange 5R (Cela- 
nese) 

Erie Fast Orange A (National) 

Erie Fast Orange CG (National) 

Pontamine Fast Orange S (Du 
Pont) 

Pontamine Orange 4G (Du Pont) 

Pontamine Orange R (Du Pont) 


397 


Red and Pink 
Chlorantine Fast Bordeaux 2BL 
(Ciba) 
Chlorantine Fast Red 7BL (Ciba) 
Erie Fast Scarlet 4BA (National) 
Erie Fast Scarlet YA (National) 
Erie Pink 2B (National) 
Pontamine Fast Red SBL (Du 
Pont) 
Pontamine Fast Scarlet 8BS (Du 
Pont) 


Violet 


C.R. Cotton Violet BBR (BDC & 
DCA) 


Yellow 
Chrysophenine Extra (National) 
C.R. Dianol Fast Yellow BS (BDC 

& DCA) 
Direct Yellow G (Newport) 
Erie Yellow F (National) 
Pontamine Yellow SX (Du Pont) 


The following direct cotton dyes from various sources have 


been stated to leave the accompanying acetate silk white. 


Un- 


doubtedly they will vary widely in this property as in all others, 
but most of them will give good results when used for light shades 


by the proper methods: 


Yellow 


Oxydianil Yellow G and O (MLB) 

Dianil Direct Yellow S (MLB) 

Direct Golden Yellow 2G (Ciba) 

Direct Yellow TG Extra conc., and 
bik conc. (Ciba) 

Dianil Yellow GC, and 2R (MLB) 

C.R. Chlorazol Yellow G (BDC) 

C.R. Chlorazol Fast Yellow B, FG, 
and NX (BDC) 

Direct Fast Yellow 3G conc. (Ciba) 

Paramine Fast Yellow 3G (Holli- 
day) 

Chrysophenine G (Union Dye) 

Diamine Yellow CP (Cassella) 

Oxy Diamine Yellow GG and TZ 
(Cassella) 

Oxyphenine GGX (Ciba) 

Stilbene Yellow GX, and 3GX 
(Badische) 


Diamine Fast Yellow A, B, 4G, FF, 
M, and R (Cassella) 

C.R. Cotton Yellow 3G (Celanese) 

C.R. Chlorazol Cotton Fast Yellow 
BeC BD) 

Stilbene Yellow G and 3G (Bad- 
ische) 

Benzo Fast Yellow RL (Bayer) 

Diamine Fast Yellow B, G, and 
4G (Cassella) 

Yellow CW 


Art Silk Bright 
(Geigy) 
Art Silk Chrysoine RCW (Geigy) 
Chloramine Fast Yellow B (Bayer) 
Chloramine Yellow M (Bayer) 
Direct Yellow R Extra (Bayer) 
Pontamine Diazo Yellow 2GL (Du 
Pont) 
Pontamine Fast Yellow B (Du 
Pont) ; 


398 
Orange 
Dianil Fast Orange 2R and O 
(MLB) 


Direct Brilliant Orange RAF Ex- 
tra conc. (Ciba) 

Direct Fast Orange SE (Ciba) 

C. R. Chlorazol Cotton Fast Orange 
5R (BDC) 

Paramine Fast Orange D, and G 
(Holliday) 

Pyramine Brilliant Orange 3RS 
(Holliday) 

Chlorazol Fast Orange AG (BDC) 

Pontamine Fast Orange 2G and ER 


(Du Pont) : 
Art Silk Orange BCW (Geigy) 
Art Silk Fast Orange 

(Geigy) 


Dianil Orange G (MLB) 
Direct Brilliant Orange RAF Ex- 
tra conc. (Ciba) 


Diamine Brilliant Orange SS 
(Cassella) 

Diamine Fast Orange EG and ER 
(Cassella) 

Diamine Orange D and G (Cas- 
sella) 

Benzo Fast Orange WS (Bayer) 


Chloramine Orange G (Bayer) 
C.R. Chlorazol Fast Orange R and 
AG (BDC and DCA) 


Red and Pink 


Diamine Fast Red 8BL (Cassella) 

Diamine Brilliant Rubine S (Cas- 
sella) 

Diamine Azo Scarlet 4BL Extra, 
6BL Extra, 8BL Extra. Diazo- 
tized and developed with B-naph- 
thol (Cassella) 

Diamine Azo Fast Red 5B, 6B. 
Diazotized and developed with B- 
naphthol (Cassella) 

Diamine Azo Bordeaux B, R. Dia- 
zotized and developed with B- 
napththol (Cassella) 

Dianil Light Red 6BL, and 8BW 
(MLB) 

Dianil Fast Red K (MLB) 

Thiazine Red GXX (Badische) 

Direct Fast Scarlet BCW, 3BCW 
and SCW (Noil) 

Direct Fast Red FCW (Noil) 

Pontamine Fast Pink BL (Du 
Pont) 


ACETALE Sluice 


Pontamine Fast Scarlet 4BS (Du 
Pont) 

Pontamine Red 12B Conc. (Du 
Pont) 

Pontamine Diazo Red 5BL and 
7BL (Du Pont) 

Pontamine Diazo Bordeaux 7BL 
(Du Pont) 

Oxyamine Fast Pink B (Badische) 

Thiazine Red G and R (Badische) 

Cotton Pink GN ‘and BN (Bad- 
ische) 

Benzo Fast Eosine BL (Bayer) 

Benzo Fast Pink 2BL (Bayer) 

Benzo Fast Red 8BL (Bayer) 

Art Silk Fast Red CW (Geigy) 

Art Silk Red FCW (Geigy) 

Dianil Light Red 8BW, and 12BW 
(MLB) 

Direct Rose T 

Cotton Red A 

Oxamine Light Pink BBX (Bad- 
ische) 

Pontamine Diazo Scarlet 2BW (Du 
Pont) 

Direct Garnet BCW (Noil) 

Paramine Fast Pink B (Holliday) 

C.R. Chlorazol Fast 
(BDC) 

C.R. Chlorazol Fast Red K (BDC) 

C.R. Chlorazol Scarlet 4BS (BDC) 

C.R. Chlorazol Fast Eosine B 
(BDC) be 

C.R. Chlorazol Fast Bordeaux LK 
(BDC) 

C.R. Chlorazol Cotton Fast Red 
BL- (BDC) 

Chlorantine Fast Red 5BL (Ciba) 

Diamine Fast Bordeaux 6BS (Cas- 
sella) 

Diamine Brilliant Bordeaux R (Cas- 
sella) 

Dianil Fast Scarlet 4BSN, 5BSN, 
and 7BSN (MLB) 

Dianil Pink BD (MLB) 

C.R. Chlorazol Cotton Fast Pink 
2B (BDC) 

Diamine Fast Rose B, BBF, and G 
(Cassella) 

Diamine Rose B Extra, BD, FFB, 
FFB Extra, and GD (Cassella) 

Diamine Brilliant Scarlet S (Cas- 
sella) 

Diamine Fast Scarlet 7BS, 8BS, 
and GFF (Cassella) 


| 
‘ 
q 
; 


Pink BK © 


Pere eiec OL LON DYES RESULTS 


Violet 
C.R. Chlorazol Cotton Fast Violet 
BLa( BDC) 
C.R. Chlorazol Violet R (BDC) 
Diamine Heliotrope B (Cassella) 
Diamine Fast Violet FFBN, and 
FERN (Cassella) 
Diamine Fast Red Violet FR (Cas- 
sella) 
Direct Violet NCW (Noil) 
Pontamine Diazo Violet BL (Du 
Pont) 
Chloramine Violet FFB (Bayer) 
Chlorantine Fast Violet 4BLN, and 
2RL (Ciba) 
Pontamine Brilliant Violet (Du 
Pont) 
Blue 


Melanthrine BHX (Ciba) 

Chlorantine Fast Blue 4GL (Ciba) 

C.R. Chlorazol Blue B, and 3B 
(BDC) 

C.R. Chlorazol Sky Blue FF, and 
GW (BDC) 

C.R. Chlorazol Fast Blue 2B 
and 2BN (BDC) 

C.R. Chlorazol Cotton Fast Blue 
4GL, and FFB (BDC) 

Direct Blue A 

Direct Deep Blue CW (Noil) 

Dianil Pure Blue PH (MLB) 

Dianil Fast Blue RL, GL, and 4GL 
(MLB) 

Paramine Sky Blue FF (Holliday) 

Paramine Blue 2B New (Holliday) 

Diamineral Blue BF (Casella) 

Diaminogene Blue NBB. Diazotized 
and developed with B-naphthol 
(Cassella) 

Diaminogene Sky Blue. Diazotized 
and developed with B-naphthol 
(Cassella) 

Dianil Blue H6G (MLB) 

Brilliant Dianil Blue 3G 

Direct Blue 2B Conc., and 3B conc. 
(Ciba) . 

Diamine Fast Blue F3B, F3G, FFB, 
and FFG (Cassella) 

Diamine Blue 3B (Cassella) 


Diamine Brilliant Blue G (Cas- 
sella) 

Diamine Fast Brilliant Blue R 
Cassella) 


Diamine Sky Blue FF (Cassella) 
Diamine Dark Blue B (Cassella) 
Oxy Diamine Blue PG (Cassella) 


399 


Dianil Blue H3G, H2G, B, G, and 
R (MLB) 

Direct Navy RCW (Noil) 

Diaminogene B, diazotized and de- 
veloped with resorcinol or B- 
naphthol (Cassella) 

Oxamine Blue B, 3B, 4B, 5B, and 
GN (Badische) 

Oxamine Light Blue B, BG, and G 
(Badische) 

Oxamine Pure Blue 5B, and 6B 
(Badische) 

Direct Blue 2BCW (Noil) 

Cotton Brilliant Blue RCW (Noil) 

C.R. Cotton Diazo Blue BH (Cel- 
anese) 

C.R. Cotton Fast Blue 4GL (Cel- 
anese ) 

Pontamine Fast Blue RL (Du 
Pont) / 

Pontamine Sky Blue 6BX (Du 
Pont) 

Pontamine Diazo Blue BR, and 
3G (Du Pont) 

Oxamine Dark Blue BG (Badische) 

Art Silk Fast Blue CW (Geigy) 

Art Silk Bright Blue CW (Geigy) 

Benzo Fast Blue 4GL and FFL 
(Bayer) 

Benzo Sky Blue (Bayer) 

Brilliant Fast Blue 3BX (Bayer) 

Direct Sky Blue A conc., and 6B 
conc. (Ciba) 


Green 
Erie Green MRS (National) 
Direct Green BCW (Noil) 
Direct Dark Green BGCW (Noil) 
Erie Blue Green CW (National) 
C.R. Chlorazol Fast Green (BDC) 
Chlorantine Fast Green B (Ciba) 
Diamine Nitrazole Green ‘BB 
coupled with Nitrazole CF (Cas- 
sella) 
Diamine Green HS (Cassella) 
Diamine Dark Green NZ (Cas- 
sella) 


Brown 


Erie Brown 3RB (National) 

Direct Brown CCW, RCW, MCW 
and BCW (Noil) 

Direct Fast Brown AHPCW 
(Noil) 

C.R. Cotton Drab Brown'L (Cela- 

nese) 


C.R. Cotton Brown 2RL (Celanese) 


400 


Chlorantine Fast Brown 3GL 
(Ciba) 

C.R. Cotton Tan CH 

C.R. Chlorazol Drab RH (BDC) 


C.R. Chlorazol Brown PB (BDC) 


C.R. Chlorazol Nigger Brown 
(BDC) 

C.R. Chlorazol fae Sate No. 1, 
and No. 2 (BD 


C.R. Chlorazol Bee Brown 2RL 


(BDC) 

C.R. Chlorazol Cotton Drab Brown 
L (BDC) 

Diamine Bronze Brown PE (Cas- 
sella) . 

Diamine Fast Brown GB (Cas- 
sella) 

Pontamine Fast Brown RK (Du 
Pont) 

Art Silk Tan CW (Geigy) 

Art Silk Nigger Brown 
(Geigy) 

Black and Gray 


Benzo Fast Black L (Bayer) 
Erie Black NR (National) 
Dianil Black A2B, ES, and FDX 


(MLB) 

Paramine Black BH, and SW 
(Holliday) 

petenes Burl Black RMW (Holli- 

y) 

Direct Black GS 

Zambesi Black V (AGAF) 

Diamine Black HW (Cassella) 

Diamine Black BH diazotized and 
developed with resorcinol or B- 
naphthol (Cassella) 

Diaminogene OB and OT diazo- 
tized and developed with resorci- 
nol or B-naphthol (Cassella) 


Oxamine Black BHN (Badische) 
Noppen Black B 


CW 


ACETATE Sik 


Cotton Black 3GCW (Noil) 
Develop Black BHCW (Noil) 4 
C.R. Chlorazol Black BH and GF 
(BDC) 4 
Direct Fast Black HWCW (Noil) — 
C.R. Cotton Fast Black 3G (Cela-— 


nese) 
Chlorazol Black LF (BDC) ' 
Diamine Fast Black C conc. (Cas- — 

sella) q 
Plutamine Black A . 
C.R. Cotton Black M (Celanese) — 
Dianol Black DL (MLB) ’ 
Diazo Black BHN (Bayer) 
Direct Black VT (Bayer) 
Pontamine Diazo Black BH cone. 

(Du Pont) | 
Pontamine Fast Black LN (Du ~ 


Pont) 
Diazo Black RS (Newport) 
Oxamine Black RN and BHN, 
diazotized and developed with — 
resorcinol (Badische) | 
Oxydiamine Black JW Extra conc. — 
(Cassella) 
Art Silk Jet Black CW (Geigy) 
Art Silk Black CW (Geigy) 
Oxamine Light Gray EB (Bad- — 
ische) ; 
Dianil Fast Gray 2BN, and 2BL 
(MLB) 
C.R. Chlorazol Drab RH (BDC) 
C.R. Chlorazol Fast Gray (BDC) — 
Diamine Fast Gray BN (Cassella) — 
Diamine Gray G (Cassella) | 
C.R. Cotton Fast Gray B (Cela- — 
nese) . 
C.R. Chlorazol Fast Black N (BDC 
and DCA 
C.R. Chlorazol 
(BDC and DCA) 
Cotton Black AC (Badische) 


Certain direct cotton dyes withstand diazotization and develop- — 
ment very well and for this reason are particularly adapted for cer- — 
tain work where the developed colors are to be used on the acetate ~ 
silk. The following dyes belong to this class and do not stain Cela- — 


nese: 
C.R. Chlorazol Fast Scarlet 4BS 
C.R. Chlorazol Fast Orange AG 


and R 
C.R. Chlorazol Fast Yellow B, FG 
and NX 


Chlorazol Fast Blue 2BN 
Chlorazol Yellow GX 


GR; 
ee 
C.R. Chlorazol Green 
Cig 


Chlorazol Dark Green PL 


Black and LH 


Pere meOllTON DYES RESULTS 


401 


Direct cotton dyes which stain Celanese very slightly by Method 


No. 105: 


Du Pont Thioflavine S 

Pontamine Fast Yellow 4GL 

Pontamine Light Yellow 5GX 

Pontamine Brown R 

Du Pont Purpurine 4B conc., and 
10B conc. 

Pontamine Bordeaux B 


Pontamine Scarlet B 

Pontamine Violet N 

Pontamine Blue AX 

Pontamine Copper Blue RRX 
Pontamine Brilliant Green GX 
Pontamine Diazo Orange 
Pontamine Diazo Scarlet A, and R 


The following Ciba direct cotton dyes stain Celanese slightly: 


Chlorantine Fast Yellow RL and 
4GL 

Direct Fast Scarlet SE 

Direct Rubine Conc. 

Chlorantine Fast Violet BL 


Cupranil Brown G (A union dye) 

Direct Brown M Conc., and MR 
Conc. 

Chlorantine Fast Black BL 


The following direct cotton dyes stain acetate silk more or less, 
particularly in a short dye bath or in the application of heavy 
shades and are therefore not recommended for acetate silk white or 


contrasting color effects: 


Yellow 
Aurophenine O (MLB) 
Pyramine Yellow G (Badische) 
Dianil Yellow 3G (MLB) 
Oxamine Fast Yellow B (Badische) 


Orange 
Cotton Orange G and R (Badische) 


Pyramine Brilliant Orange 3RS 
Dianil Orange GS (MLB) 


Red and Pink 
Cotton Fast Red 8BS (Badische) 
Oxamine Light Red 4B and E8B 
(Badische) 
Oxamine Light Pink BX (Bad- 


ische) 

Dianil Fast Scarlet 8BS, and GSN 
(MLB) 

Dianil Light Red 8BL, and 12BL 
(MLB) 


Cotton Pink BN, and GN (Bad- 
ische) 

Thiazine Red R (Badische) 

Dianil Pink BD (MLB) 


Oxamine Brilliant Red B (Bad- 
ische) 


Violet 
Oxamine Violet (Badische) 
Oxamine Brilliant Violet B, and 
RR (Badische) 
Oxamine Light Violet B, and RR 
(Badische) 
Direct Fast Violet 4B (Peerless) 


Blue 


Oxamine Dark Blue BG (Badische) 

Dianil Fast Blue RL (MLB) 

Brilliant Dianil Blue 6G, and R 
(MLB) 


Brown 
Thiazine Brown G and R (Bad- 
ische) 


Black 


Burl Black B (Badische) 
Chlorazol Black E Extra (stains 
Celanese a deep reddish-gold) 
Cotton Black AC (Badische) 
Oxamine Black RN (Badische) 


402 


ACETATE SILK 


The following direct cotton dyes are sometimes used to dye ace- — 
tate silk and may therefore have a certain usefulness on acetate 
silk-cotton unions for solid shades: 


Paramine Orange G and R 
Pyramidol Brown BG 


Paramine Yellow 2G 
Paramine Brown G 


The following cotton and union dyes have been suggested as 
suitable for use on unions containing acetate silk white or contrast- — 


ing colored effects: 


Diamine Fast Yellow A, B, FF, M, 
and R (Cassella) 

Oxydiamine Yellow TZ (Cassella) 

Diamine Yellow CP (Cassella) 

Union Fast Yellow G (Cassella) 

Diamine Orange D (Cassella) 

Diamine Brilliant Orange SS (Cas- 
sella) 

Diamine Fast Scarlet 4BS, and 7BS 
(Cassella) 

Diamine Rose BD, and GD (Cas- 
sella) 

Diamine Fast Rose BBF (Cas- 
sella) 

Diamine Fast Red 8BL (Cassella) 

Diamine Fast Rubine FB (Cas- 


sella) 
Diamine Brilliant Bordeaux R 
(Cassella) 


Diamine Fast Red Violet FR (Cas- 
sella) 

Diamine Heliotrope B (Cassella) 

Diamine Fast Brown GF (Cassella) 

Diamine Fast Blue C, CG, F3B, 
FFG, and F3G (Cassella) 

Oxydiamine Blue 5G, PB, and PG 
(Cassella) 

Diamine Fast Brilliant Blue R 
(Cassella) 


Diamineral Blue R (Cassella) 

Diamine Steel Blue L (Cassella) 

Diamine Brilliant Blue G (Cas- — 
sella) ; 

Diamine Dark Blue B (Cassella) 

Union Fast Blue MB, and FR 
(Cassella) 

Union Fast Gray BR (Cassella) 

Oxydiaminogene OB (Cassella) 

Diamine Black BH (Cassella) ’ 

Para Diamine Black BF Extra 
conc. and FFB Extra cong 
(Cassella) : 

Union Black VA . 

Diamine Azo Scarlet 4BL Extra — 
6BL Extra, and 8B Extra diazo- — 
tized and developed with B- 
naphthol (Cassella) 

Diamine Azo Fast Red 5B, and 6B 
diazotized and developed with B- — 
naphthol (Cassella) ! 

Diamine Azo Bordeaux B, R, and — 
K3B_ diazotized and developed — 
with B-naphthol (Cassella) 

Diamine Azo Navy Blue B cone. 
diazotized and developed with © 
B-naphthol (Cassella) 

Diaminogene Blue GG and NBB 
diazotized and developed with — 
B-naphthol (Cassella) 


The following cotton and union dyes stain acetate silk more or 
less and therefore should not be used for heavy shades on wool 
in the presence of acetate silk white or contrasting colored effects: — 


Diamine Fast Yellow 4G (Cassella) 

Diamine Fast Orange ER (Cas- 
sella) 

Diamine Scarlet 10BS, and GG 
(Cassella) 

Diamine Purpurine 6B (Cassella) 


Diamine Heliotrope G (Cassella) 
Union Fast Heliotrope B (Cassella) 
Diamine Red 4B (Cassella) 
Diamine Brilliant Rubine S (Cas- — 
sella) 
Diamine Violet Red (Cassella) 


PineewecOl LON DYES RESULTS 


Diamine Violet N (Cassella) 

Diamine Fast Violet BBN and 
FFBN (Cassella) 

Oxydiamine Violet B (Cassella) 

Union Violet KB (MLB) 

Chlorazol Fast Heliotrope BK 

Diamine Brown ATC, and M (Cas- 
sella) 

Diamine Fast Brown GB, and R 
(Cassella) 

Diamine Catechine 3G (Cassella) 

Union Fast Brown G (Cassella) 

Diamine Green G (Cassella) 

Union Fast Green GG (Cassella) 


403 
Diamineral Blue BB. and CVB 
(Cassella) 
Diamineral Brilliant Blue B (Cas- 
sella) 


Union Sky Blue KF (Cassella) 

Union Blue BB, BJ, KG, and KHS 
(Cassella) 

Union Navy Blue KPB, and KO 
(Cassella) 

Union Gray BBG (Cassella) 

Diaminogene Extra, and B (Cas- 
sella) 

Diamine Black HW (Cassella) 

Oxydiamine Black A (Cassella) 


The following cotton and union dyes stain aceate silk consider- 
ably and are therefore not suited for acetate silk white or contrast- 
ing color effects. Some may prove useful for solid shades: 


Thioflavine S (Cassella) 

Diamine Orange B and F Cas- 
sella) 

Oxydiamine Orange G (Cassella) 

Union Fast Orange G and R (Cas- 
sella) 

Diamine Scarlet B and 3B (Cas- 
sella) 

Diamine Fast Red F (Cassella) 

Diamine Red 6B, and 10B (Cas- 
sella) 

Union Fast Red R (Cassella) 

Diamine Purpurine B (Cassella) 

Diamine Bordeaux B, and S Cas- 
sella) 

Diamine Fast Bordeaux 6BS (Cas- 
sella) 

Union Fast Bordeaux FR (Cas- 
sella) 

Diamine Brown MR, and B (Cas- 
sella) 

Oxydiamine Brown 3GN, G and 
RN (Cassella) 

Diamineral Brown G (Cassella) 

Diamineral Catechine G, and B 
(Cassella) 


I 


Union Fast Brown GG, L, TD, and 
MP (Cassella) 

Union Dark Brown A (Cassella) 

Oxydiamine Violet G, and BF (Cas- 
sella) 

Diamine Green B, and HS (Cas- 
sella) 

Diamine Dark Green N' (Cassella) 

Union Green VT (Cassella) 

Union Olive KD (Cassella) 

Light Blue 5380 (Cassella) 

Oxydiamine Blue G (Cassella) 

Union Navy Blue VB (Cassella) 

Union Fast Dark Blue B, and R 
(Cassella) 

Diamine Fast Gray BN (Cassella) 

Diamine Black DN (Cassella) 

Diamine Fast Black X (Cassella) 

Oxydiamine Black JEI, JW, UI, 
and G Extra conc. (Cassella) 

Diamine Aldehyde Black SB (Cas- 
sella) 

Union Fast Black SB (Cassella) 

Union Black S, BG, 3B, KAX, BD 
conc., and KRN conc. (Cassella) 


CHAPTER XXaias 


ACETATE SILK AND WOOL OR. TRUE SILK COMBI§ 


NATIONS 


Due to the fact that the dyeing properties of acetate silk re-— 


semble those of wool more nearly than they do those of any other 


fiber, it is not surprising that it is more difficult to find acetate silk — 


dyes which do not stain wool than in the case of acetate silk dyes 


which do not stain cotton or the older rayons. However, due to 
the sulfonic acid groups in most acid dyes, it is not nearly so diffi- — 


cult to find wool dyes which do not stain acetate silk. All of the 
older rayons, viscose, cuprammonium, and nitro, have quite differ- 
ent dyeing properties from those of wool and may therefore be 
used for white or contrasting color effects in woolen materials 
under certain conditions. As they are not seriously affected by 
boiling water, they frequently offer some advantages over acetate 


silk for multicolored effects in that a wider selection of acid dye- — 


stuffs may be used on the wool without resort to any special dye- 
ing methods or precautions. 
Nevertheless, where a three of four color combination on as 


many different fibers, including wool, is desired, acetate silk again — 
comes into its own, due to the fact that it has quite different — 
dyeing properties from those of the other fibers. The usefulness — 


of acetate silk in wool unions is also increased by the fact that 
under special conditions Celanese and similar brands of hot-water 


sensitive acetate silks may be present in a boiling dye bath with- — 


out loss of luster.* 
At the present time in America, the strong tendency to push 


dyeing production and at the same time lower costs, brings a | 


strong demand for a cheap and simple method of dyeing combi- 
nations of every commercial textile fiber in all imaginable shades 


simultaneously in the one dye bath. While some really wonderful — 
results are actually obtained by some of these “combination-— 


cover-all” processes, they are certainly not to be recommended 


*See Method No. 85, Chapter XXV. 
404 


a a 


TRUE SILK COMBINATIONS 405 


where the very best results are desired. In general, each such 
combination process requires a very special consideration of all 
factors and dyes involved, as well as the fastness desired, and 
very careful laboratory tests should be made before attempting 
actual plant operations. 

Wool and acetate silk combinations are more difficult to handle 
than acetate silk-cotton unions; for while it is not hard to find 
wool-dyes which do not stain acetate silk, most of the acetate silk 
dyes stain or even dye wool, and frequently they dye the wool a 
different color from that of acetate silk. For instance, Cit- 
ronine Y conc., gives a greenish-yellow color on acetate silk and 
a reddish-yellow on wool. Cardinal Red J gives a pink on acetate 
silk and a full red on wool. Magenta and Malachite Green, both 
basic dyes, give approximately the same color on acetate silk 
and wool but in the case of Celanese, the wool is dyed the deeper 
shade. With Lustron the reverse is the case. Tannin Pink C 
leaves Celanese white in wool unions. 

Most of the Cellutyl and Acetate brands of dyestuffs stain or 
dye wool. Method No. 106 covers the application of the Setacyl 
Direct dyes to acetate silk in combination with true silk for multi- 
color effects. Probably in the case of wool the best results are 
obtained in a similar manner. The Cellit Fast dyes also stain 
both wool and true silk. ; 

The older acid dyes that are applicable to acetate silk usually 
give only light shades on it, even from a short dye bath. However, 
this is not at all the case with the special acetate silk dyes of this 
classification, such as the Setacyl Direct and Cellit Fast dyes, 
which give full shades on acetate silk. 

Method No. 106: Setacyl Direct Dyes on Acetate Silk-True 
Silk Unions. In dyeing the acetatae silk in combination with true 
silk for multicolor effects, the addition of 5 per cent of acetic acid, 
after 20 minutes at 82° C., will feed the acid dyes onto the real 
silk from the same dye bath. 


The Ionamines on Acetate Silk-Wool or True Silk Unions 


As mentioned under the Ionamines,” the undissociated Ionamines 
dye wool as acid dyes while the hydrolyzed Ionamines. dye the 


>See Chapter XX. 


406 ACETATE SILK 


acetate silk, usually giving quite different shades on the two fibers. 
True silk appears to be dyed by both the hydrolyzed and unhy- 
drolyzed Ionamine at the same time. Upon diazotization and 
development, the differences in shade between the three fibers 
becomes more pronounced. As the Ionamines are applied to ace- 
tate silk from an acid dye bath, they can be used in combination 
with other acid dyes on acetate silk-wool unions. For example,” 
an orange shade on acetate silk and a navy blue to black on wool 
may be obtained by applying Ionamine B and Coomassie Navy 
Blue from an acid dye bath. 


Dispersol Dyes on Acetate Silk-Wool or True Silk Umions 


As a class, most of the dispersol dyestuffs either considerably 
stain or dye wool and true silk. With the exception of S.R.A. 
Pure Yellow I, which dyes animal fibers, the S.R.A. dyes do not 
completely dye wool but most of them stain it more or less, ac- 
cording to the conditions and particular dyestuff used. Most of 
the S.R.A. dyes also stain true silk and the amount of staining 
varies with different varieties of true silk. Where white true silk 
effects are desired, the S.R.A. dyes must be selected for this pur- 
pose. Certain of the S.R.A. yellows, blues, violets and heliotropes 
have been recommended for this purpose. Where it is desired to 
clear the stained wool or true silk, soaping after the dyeing is com- 
pleted, as directed under Clearing Unions, Chapter XXXV, usu- 
ally clears up the wool or true silk to some extent. This may be 
supplemented by treatment in a peroxide bleach bath if a white 
effect is desired. 

Some dispersol dyes give spore the same color on both 
the acetate silk and wool, but usually the acetate silk is dyed a 
deeper shade. However, by a proper manipulation of the acidity 
and temperature, or by adding a small amount of suitable acid 
dye to the bath, it is sometimes possible to get solid shades on ace- 
tate silk-wool or true silk combinations with dispersol dyes. Dur- 
anol Black G dyes wool to almost the same shade as the acetate 
silk from an acid dye bath. In fact the Duranol and Dispersol 
dyes all stain wool and true silk to some extent in an acid dye bath 
and most of the Duranol dyes from a neutral or alkaline dye bath. 


TRUE SILK COMBINATIONS 407 


Nevertheless, in spite of all this, it is possible to obtain contrasting 
multicolor effects on acetate silk-wool or true silk unions by 
properly selecting the dyestuffs and method of application. 

As the Celanthrene dyes stain both wool and true silk, they are 
not recommended for use on acetate silk unions containing these 
fibers. The animal fibers are not well dyed as the color is largely 
removed by repeated washing. 

In applying the dispersol dyes to acetate silk-wool or true silk 
unions, it is usually best to dye the acetate silk first. In some cases 
the wool dyestuff may then be added to the dispersol dye bath after 
the dispersol dye is partly exhausted, as in applying the direct dyes 
to the cotton of the corresponding unions. This method works 
very well with all of the dispersol dyes (S.R.A., Duranol, Cela- 
tene, etc.) when neutral dyeing wool dyestuffs are used. When 
the dispersol dyestuff is solubilized by means of a fatty agent 
(S.R.A.) and must be applied in a neutral or alkaline dye bath, 
acid dyeing wool colors cannot be used in the same dye bath with 
the dispersol dye, and the wool dyes must be applied from a fresh 
dye bath. Otherwise the acid used in feeding on the wool dyestuft 
will cause a separation of the fatty acid of the dispersing agent 
in the dye bath. 

In applying certain dispersol dyes which are prepared without 
the use of fatty dispersing agents, it is frequently possible to dye 
both the acetate silk and wool in one dye bath in the presence of an 
organic acid. However, as usual, it is necessary to pay close at- 
tention to temperatures in order to match the shade of both the 
acetate silk and wool. Both the Duranol and Celatene dyes may 
be used in this manner. In any case only easily leveling wool dyes 
should be selected which are applicable at 80° C. (176° F.), unless 
it is desired to use Method No. 85. Only organic acids (preferably 
formic acid) should be used in cross-dyeing the wool as the 
S.R.A. dyes are not all fast to cross-dyeing with mineral acids. 
With the exception of S.R.A. Blues I and II, the S.R.A. dyes with- 
stand wool cross-dyeing with organic acids very well. 

In dyeing Lustron-wool unions or woolen materials containing 
Lustron effects, the goods may be dyed at the boil, but it 1s best 
to use only organic acids to aid the exhaustion, and the usual addi- 


408 ACETATE SILK 


tion of inorganic salts such as Glauber’s salt or ammonium sulfate, — 
to the boiling wool dye bath, is of course not at all detrimental to 
the luster of the acetate silk. On account of its superior resistance 
to boiling, Lustron has a very decided advantage for use in woolen” 
materials which are to be dyed. It also appears to be particularly 
resistant to staining by some acid dyes, which is of course ad-— 
vantageous. However, Lustron is more susceptible to acids than | 
Celanese. 

| 


Where Celanese or Rhodiaseta are present in the combination, 
the wool should be dyed at temperatures below 85° C. (185° F.), 
as in Methods No. 107 and No. 108, wherever possible. If these 
methods will not suffice, Method No. 85 must be used. In dyeing” 
acetate silk-true silk unions where the true silk must be boiled off, — 
this may be done below 85° C. (185° F.) or at the boil, as covery 
by British Patent No. 206,113.° 

Method No. 107: Dyeing Celanese and Wool or True Sik byl 
the One Bath Process. Enter the goods into the cold dye bath 
containing up to 50 per cent of the acetate silk dyestuff, 10 per | 
cent of Glauber’s salt, and a small amount of organic acid. Gradu- | 
ally raise the temperature during about 2 hours, adding more dye- | 
stuffs and acid as required, to about 80° C. (176° F.). Where 
Lustron is present, higher temperatures may be used. The S.R.A. 
dyes should not be applied by this method, as the acid causes a 
separation of the fatty acids of the solubilizing agent, but it is 
suitable for the application of the Duranols and Celatenes. | 

Method No. 108: Dyeing Acetate Silk and Wool or True Suk 
by the Two Bath Method. Dye the acetate silk first by Method | 
No. 74 and rinse well. Then dye the wool in a fresh bath con- 
taining the wool dye, 10 per cent of Glauber’s salt, and up to 
4 per cent of formic acid. Enter the material at 45° C. (113° F.), 
and during a half-hour raise the temperature to 80° C. (176° F.). 
Dye at this temperature for an hour and a half or two hours. 
Higher temperatures are possible if Lustron is present. All of | 
the dispersol dyes are applicable by this method.* 

For solid colors upon acetate silk-true silk unions with the Di- 


rect Azonines on the acetate, the wet out union is entered into 
err emaieearan act! ‘ 

“See Chapter IX. 

4See Chapter XXI. 


FRUE SILK COMBINATIONS 409 


a dye bath containing 5 to 8 ounces of soap per 10 gallons of 
liquor and the necessary quantity of dyestuff previously mixed 
with hot water. The goods are worked for 45 to 60 minutes at 
70° C. (160° F.), rinsed, and the true silk dyed with acid dye- 
stuffs at 50 to 60° C. (120 to 140° F.), with acetic or formic 
acid. In case two-color effects are desired, the dyeing is con- 
ducted in exactly the same manner except that a lower tempera- 
ture, say 50° C. (120° F.), is used in dyeing the acetate silk to re- 
tard the staining of the true silk. As some of the Azonine Direct 
dyes stain the true silk somewhat, in many cases better results are 
obtained by dyeing the true silk a darker color or shade than the 
acetate, making due allowance for the staining of the true silk. 


Solid Black on Acetate Silk-Wool Unions 


A solid black on acetate silk-wool or true silk unions may be ob- 
tained! by using a 20 per cent of S.R.A. Black IV, developed 
with B-hydroxynaphthoic acid, on the acetate silk. A deep blue- 
black color on the wool or true silk may be obtained with about 
5 per cent of C.R. Wool Black 10BW. A jet black is obtained 
with 4 per cent C.R. Wool Black 10BW, 4 per cent C.R. Wool 
Crystal Orange, 10 per cent Glauber’s salt, and 3 per cent sulfuric 
acid. Dye for an hour at 80° C. (176° F.). Another method is 
to use C.R. Wool Red 10B and C.R. Wool Light Yellow 2G for 
shading, in place of the Crystal Orange. ‘The Black 10BW may 
be substituted with C.R. Wool Black 10B. 

Solid shades of black on acetate silk-wool unions may also be 
obtained with Cellutyl Union Blacks No. 1 and No. 2. These are 
applied with 2 per cent of formic acid at 80° C. (176° F.) for 
about 45 minutes. The goods are then rinsed thoroughly and 
cold diazotized with 3 per cent of sodium nitrite and 10 per cent of 
32° Tw. (sp. gr. 1.160) hydrochloric acid for 30 minutes. It is 
then rinsed again and developed with 8 per cent of B-hydroxy- 
naphthoic acid at 50° C. (120° F.) for a half hour, washed and 
dried. 

In dyeing unions of Celanese and wool or true silk by Method 
No. 108, the following dyes have been suggested. It is of course, 
understood that most of the S.R.A. dyes stain wool. 


410 


Mode Shades: Grays, Fawns, Putty, 
Mole, etc. 


Celanese: S.R.A. Pure Yellow I or 
S.R.A. Golden Orange 

VIII 

S.R.A. Orange II 

S.R.A. Violet II 

S.R.A. Blue III 

Wool or Silk: C.R. Wool Light 

Yellow 2G 
C.R. Wool Red 10B 

C.R. Wool Pink B 
C.R. Wool Blue SAP 


Sky Blue and Saxe 


Celanese: S.R.A. Blue IV 
Wool: C.R. Wool Blue SAP 


Lemon Yellow 
Celanese: Se Pure Yellow I or 


Wool: oe Wool Light Yellow 


ACETATE SILK 


Celanese: 


Wool: 


Celanese: 


Wool: 


Celanese: 


Wool: 


Orange 
S.R.A. Orange I or II 
C.R. Wool Crystal Or- 
ange. 


Green 
S.R.A. Blue IV and ; 
S.R.A. Golden Yellow — 
VIII or IX. ES 
C.R. Wool Blue SAP & 
SS Wool Light Yellow 


Black 
S.R.A. Black IV, as in 
Method No. 135, with 
B-hydroxynaphthoic 
acid. 
C.R. Wool Black 10B or 
10BW 


C.R. Wool Red 10B 
ie Wool Light Yellow 


Where it is desired to dye the Celanese and wool or silk in a 
single bath, Method No. 107 should be used with the following 


dyes: 

Gray 
R.A. Pure Yellow I 
R.A. Golden Yellow 
VIll 
R.A. Orange Il 
S.R.A. Violet II 
S.R.A. Blue ITI 
Diphenyl Fast Gray B 


conc. 
Patent Blue No. 9879. 


Fawn 


Same as Gray above 
Diphenyl Fast Brown 


GN ext. 

Diphenyl Chlorine Yel- 
low FF 

Shade with Patent Blue 
if desired. 


Celanese: 


>: 
nop 
S. 
Wool: 


Celanese: 
Wool: 


Lemon 


Celanese: S.R.A. Pure Yellow I or 


IT 
Wool: Quinoline Yellow. 


Red 


S.R.A. Red I or III 
Coomassie Milling Scar- 


Celanese: 
Wool: 


Celanese: 


Wool: 


Celanese: 


Wool: 


Celanese: 


Wool: 


let G 
Brilliant Milling Violet 
S4B. 


Green 


S.R.A. Blue IV 

S.R.A. Golden Yellow 
VIII 

Patent Blue No. 9879 

Diphenyl Chlorine Yel- 
low FF, or 

Chrysophenine G. 


Bright Blue 

S.R.A. Blue IV 

Patent Blue No. 9879 
aioe Milling Violet 


Navy Blue 

S.R.A. Blue V 

S.R.A. Red I 

S.R.A. Orange I 

Coomassie Navy Blue 
2RNX 

Shaded with Chrysophe- 
nine G, if desired. 


TRUE SILK COMBINATIONS 411 


The following wool dyes are applicable by Method No. 108: 


C.R. Wool Red 10B Coomassie Fast Black B 
C.R. Wool Blue R Eosine BS and YS 
Coomassie Scarlet 9012 K Azo Geranine B 
Coomassie Milling Scarlet G Alizarine Delphinol SE 
Coomassie Acid Blue RL Disulphine Blue V 
Coomassie Navy Blue 2RNX andG __Lissamine Violet 2R 
Coomassie Violet R Acid Prune V 


Lissamine Red 6B 


The following dyes may be applied by Method No. 107 without 
acid: 


Coomassie Navy Blue 2RNX Rhodamine B 
Coomassie Milling Scarlet G Acid Milling Black (Stains Cela- 
Quinoline Yellow extra nese gray) 


Chrysophenine G 


The selection of suitable acid dyes for the wool, both as regards 
to applicability at low temperatures, leveling, and not staining the 
acetate silk, is of course of prime importance for success in this 
phase of the dyeing. Through the courtesy of Dr. Elvin H. Kill- 
heffer, the Newport Chemical Works have furnished some very 
interesting and detailed information comparing the staining prop- 
erties of Lustron and Celanese by their wool dyes. Their follow- 
ing lists are of particular interest in that they appear to be the 
first to differentiate between the staining properties of these two 
brands of acetate silk. The following dyes leave both Celanese 
and Lustron white: 


Yellow Newport Croceine Scarlet 3BX 
Newport Chinoline Yellow Newport Lana Fuchsine B 


Newport Fast Yellow FSW Newport Acid Fuchsine 
Newport Fast Wool Yellow G Newport Acid Phloxine 6B 
Newport Naphthol Yellow S Newport Amaranth 

Orange MBige 
Newport Fast Orange FSW Newport Patent Blue A 

Red and Pink Newport Acid Blue Black Extra 
: conc. 

Newport Acid Scarlet 2R Ne nerACaED Gees. 


Newport Azo Eosine G, and 2B 
The following acid dyes stain Lustron effects very slightly: 


Black Newport Acid Violet 4BS 
Newport Fast Acid Black N2B ine 
Violet Newport Acid Blue GR conc. 


Newport Fast Acid Violet RM Ex- Newport Fast Wool Cyanone 3R 
tra 


412 ACETATE SILK 


Orange Yellow 
Newport Orange GG conc. Newport oe Yellow 
. reen 
Newport be 0 5 Sa Nea Acid fea B conc. 
ort Fast Acid Re F Le 
Newport Acid Bordeaux Extra ewport Fast Milling Green B 


conc. Black 
; Newport Wool Black B 


Acid dyes which stain Lustron effects badly: 


Violet Black 
Newport Fast Acid Violet 10B Newport Naphthylamine Black V 
Newport Acid Violet 12B 
Yellow 
Green Newport Azo Yellow 3G 


Newport Wool Green SAN 


The following acid dyes leave Celanese effects practically white: 


Black Blue 
Newport Fast Acid Black N2B Newport Acid Blue GR conc. 
; Newport Fast Wool Cyanole 3R 
Violet 
Newport Fast Acid Violet RM Ex- Orange 


tra Newport Orange GG conc. 
Newport Acid Violet 4BS 


Acid dyes which slightly stain Celanese effects: 


Red and Pink Newport Fast Milling Green B 
Newport Fast Acid Red CB Newport Wool Green SAN 
Newnes Acid Bordeaux Extra Black andes 
onc 

Violet Newport Wool Black B 
Newport Acid Violet 12B Newport Naphthylamine Black vo 
Newport Fast Acid Violet 10B 95% Yellow 

Green Newport Metanil Yellow 


Newport Acid Green B conc. 


The following acid dye stains Celanese badly: 
Newport Azo Yellow 


The following wool dyes from various sources leave Celanese 
unstained ; 


Yellow Pontachrome Fast Yellow GW, and 
Kilton Fast Yellow 3G Extra conc. RW (Du Pont) 
(Ciba) Pontachrome Yellow SW (Du 
Cloth Fast Yellow G (Ciba) Pont) 
Tartrazine O (Du Pont) Tartrazine R Extra conc. 


Pontacyl Fast Yellow G (DuPont) ©-R. Wool Light Yellow 2G (Cela- 
Pontacyl Light Yellow 2G, and 3G nese) 
(Du Pont) C.R. Wool Yellow T (Celanese) 


TRUE SILK COMBINATIONS 


Milling Yellow O, and 3G (Cassella 
and MLB) 

Radio Yellow R (Cassella) 

Quinolin Yellow (Badische) 

Supramine Yellow R (Badische) 

Wool Fast Yellow G (Badische) 

Acid Yellow 79210 (BDC and 
DCA) 

Xylene Fast Light Yellow 2G 

Lissamine Fast: Yellow 2G (BDC 
and DCA) 

Naphthol Yellow FY (BDC and 
DCA) 

Orange 

Neolan Orange R (Ciba) 

Kiton Fast Orange G (Ciba) 

Orange G (Du Pont) 

Orange II conc. (may be applied at 
low temperatures) 

C.R. Wool Crystal Orange (Cela- 
nese) 

Primazine Orange G (Badische) 


Brown 


Resorcine Brown 3R (Du Pont) 
Pontachrome Brown RH conc., and 
SW (Du Pont) 


Red and Pink 


C.R. Coomassie Carmine 2BD, and 
2GD (BDC & DCA) 

Kiton Fast Red BL, and R (Ciba) 

Neolan Red 3B (Ciba) 

Kiton Red 6B (Ciba) 

Pontacyl Carmine 2B and 2G (Du 
Pont) 

Pontacyl Light Red BL (Du Pont) 

Pontacyl Ruby G (Du Pont) 

Pontachrome Red B (Du Pont) 

Pontachrome Fast Red E (Du 
Pont) 

C.R. Wool Fast Pink B (Celanese) 

C.R. Wool Red 5B (Celanese) 

Brilliant Milling Red R (Cassella) 

Scarlet EC (Cassella) 

Azo Red A (Cassella) 

Supramine Red B (Badische) 

Acid Rhodamine BG (Badische) 

Ponceau RR (Badische) 

Fast Ponceau BX (Badische) 

Anthosine 3B (Badische) 

Azo Carmine BX (Badische) 

Wool Red G 

Acid Scarlet 4R Extra (BDC and 
DCA) 


413 


Carmoisine WS and L9156K (BDC 
and DCA) 

Fast Red EAS (BDC and. DCA) 

Cardinal Red 3B (BDC and DCA) 

Lissamine Red 6B (BDC and 
DCA) 


Violet 

Victoria Violet L (Ciba) 

Pontacyl Fast Violet R (Ciba) 

Pontacyl Violet RL (Ciba) 

C.R. Coomassie Violet 1OBP (BDC 
& DCA) (applicable at a low 
temperature) 

C.R. Wool Violet 10B (Celanese) 

Lanacyl Violet BF (Cassella) 

Lissamine Violet 2R (BDC and 


DCA) 
Indigo (BDC and 


DCA) 


Carmime X 


Green 
Neolan Green B (Ciba) 
Kiton Fast Green B (Ciba) 
Alizarin Emerald (Du Pont) 
Pontacyl Green B, SN Extra, SF 
Yellowish, and NV conc. (Du 
Pont) 
Naphthol Green B conc. (Du Pont) 
Pontachrome Green G (Du Pont) 
Acid Green 2G conc. 
C.R. Wool Green V, and 2G (Cela- 
nese) 
Alizarin Brilliant Green (Cassella) 
Light Green SF Yellowish (Bad- 
ische) 
Neptune Green S10G 


Blue 

Kiton Pure Blue V (Ciba) 

Neolan Blue 2G, and 2R (Ciba) 

Cloth Fast Blue R (Ciba) 

Alizarin Saphirole B, and BR (Du 
Pont) 

Indigotine conc. (Du Pont) 

Pontacyl Brilliant Blue A (Du 
Pont) 

Pontacyl Fast Blue R, and 5R 
conc. (Du Pont) 

Pontachrome Blue SW (Du Pont) 

C.R. Coomassie Acid Blue R (BDC 
& DCA) 

Alizarin Dephinol BS Special (BDC 
& DCA) 

Alizarin Delphinol SE 


414 


Disulphine Blue (BDC & DCA) 
(applicable at a low temperature) 

C.R. Wool Blue V, A, and SAP 
(Celanese) 

C.R. Wool Fast Blue R (Celanese) 

Alizarin Cyanol B (Cassella) 

Tetracyanol A (Cassella) 

Formyl Blue B (Cassella) 

Lanacyl Blue BN, and RN (Cas- 
sella) 

Niaphthol Blue G (Cassella) 

Alphanol Blue BR Extra, GN, and 
5RN (Cassella) 

Lanacyl Navy Blue B (Cassella) 

Wool Fast Blue BL (Badische) 

Wool Fast Marine Blue BB (Bad- 
ische) 

Cyanthrol BGA (Badische) 

Neptune Blue BG (Badische) 


ACETATE SILK 


Lissamine Blue B (BDC and DCA) ~ 
Lissamine Navy Blue G (BDC and — 
DCA) é 
Fast Acid Blue RH (BDC and 
DCA) 
Black and Gray 


Neolan Black 2R (Ciba) 

Pontachrome Black SW (Du Pont) — 

C.R, Coomassie Blue Black G conc. 
(BDC & DCA) (applicable at 
low temperature) 

C.R. Wool Black 10B, and 10BW 
Celanese) 

Palatine Black MM and SF (Bad- | 
ische) 

Naphthalene Blue Black C (BDC 
and DCA) | 

Naphthalene Black ESNC (BDC 
and DCA) 


The following dyestuffs have been suggested for topping true 
silk in a lukewarm dye bath in the presence of acetic acid. Under 
these conditions they leave acetate silk, cotton, and the older 
rayons entirely or almost unstained: 


Quinoline Yellow and Extra (Bad- 
ische ) 

Supramine Yellow R (Badische) 

Wool Fast Yellow G (Badische) 

Acid Yellow AT (Cassella) 

Fast Acid Yellow TLN (Cassella) 

Radio Yellow R (Cassella) 

Milling Yellow O and 3G (Cas- 
sella) 

Orange II 

Orange GG (Cassella) 

Scarlet RR (Badische) 

Acid Rhodamine BG (Badische) 

Azocarmine BX (Badische) 

Supramine Red B (Badische) 

Radio Red G and VB (Cassella) 

Lanafuchsine SG, SB, and 6B (Cas- 
sella) 

Azo Red A (Cassella) 

Brilliant Cochineal 2R and 4R 
(Cassella) 

Scarlet FR and F3R (Cassella) 

Brilliant Lanafuchsine GG, SL, and 
BB (Badische) 

Alizarine Cyanole Red B_ (Cas- 
sella) 

Acid Magenta (Cassella) 

Anthosine 3B (Badische) 

Acid Violet 4RN (Badische) 


Acid Violet 3BNO 

Alizarine Direct Red BB and 5G 

Azo Wool Violet 7R (Cassella) 

Acid Violet 4RS (Cassella) 

Lanacyl Violet BF (Cassella) 

Cyananthol BGA (Badische) 

Neptune Blue BG (Badische) 

Cyanole FF extra (Cassella) 

Tetra Cyanole A and V (Cassella) 

Alizarine Cyanole B, and BSE, CA, 
GSE, and ZEF (Cassella) 

Brilliant Naphthol Blue, all brands 
(Cassella) 

Lanacyl Blue BN and RN (Cas- 
sella) 

Wool Fast Blue BL (Badische) 

Wool Fast Marine Blue BB (Bad- 
ische) 

Neptune Green SG and S10G 
(Badische) 

Light Green SF Yellowish (Bad- 
ische) 

Cyanole Fast Green G and GG 
(Cassella) 

Alizarine Brilliant Green G (Cas- 
sella) 

Radio Brown B (Cassella) 

Radio Black ST (Cassella) 


>») 
5 Se” ina as 


TRUE SILK COMBINATIONS 


415 


The following are less suitable and may stain the acetate silk 


slightly : 


Primazine Orange G (Badische) 
Fast Scarlet BX (Badische) 


Palatine Black MM and SF (Bad- 
ische) 


The following wool dyes stain Celanese slightly : 


Yellow 


Anthracene Yellow C (Bayer) 
Tropaeolin O (Cassella) 


Orange 
Brilliant Milling Orange GR (Cas- 
sella) 
Orange RO, and II conc. (Du 
Pont) 
Orange Extra (Cassella) 
Orange A Extra, and R (Badische) 
Orange EN 


Red and Pink 


Pontacyl Fast Red AS (Du Pont) 

Rosazeine B (MLB) 

Brilliant Scarlet G and GG 

Croceine AZ (Cassella) 

Brilliant Croceine 3B, 5B, M, and 
MOO (Cassella) 

Naphthol Red C (Cassella) 

Brilliant Milling Red R (Cassella) 

Milling Red B 

Azo Orseille KWS (Cassella) 


Violet 


Acid Violet 6BS (Cassella) 
Formyl Violet 10B and S4B (Cas- 


sella) 
Acid Violet 6BS (Cassella) 


Acid Violet 4RN (Badische) 


Blue 
Lanazurine K2R, and KB 
Thiocarmine R (Cassella) 
Brilliant Milling Blue B, and FF 
(Cassella) 
Alizarin Cyanol SB and SBR (Cas- 


sella) 


Brown 


Radio Brown B and S (Cassella) 
Alphanol Brown B (Cassella) 
Alizarin Cyanol Violet R (Cassella) 


Green 
Brilliant Milling Green B (Cas- 
sella) 
Anthracene Direct Green B (Cas- 


sella) 
Naphthol Dark Green G 


Black and Gray 


Pontacyl Fast Black BBO (Du 
Pont) 

Alphanol Fast Gray B (Cassella) 

Alphanol Black 3BN, and KWAN 
(Cassella) 

Naphthol Blue Black (Cassella) 

Radio Black ST, and SB (Cassella) 


The following wool dyes stain acetate silk and while useful for 
solid colors, etc., should not be used where acetate silk white 


effects are desired: 


Indian Yellow, especially the G, R, 
and FF brands 

Tropaeolin OO and G (Cassella) 

Orange Extra, R, and VI 

Rocelline 

Acid Violet 6BC (Cassella) 

Alizarin Leveling Violet BR (Cas- 
sella) 

Alizarin Cyanol EF, and BE (Cas- 
sella) 

Alkali Blue, all brands 

Alphanol Brown R (Cassella) 

Alphanol Fast Gray B (Cassella) 

Anthracite Black B (Cassella) 


Naphthylamine Black 4B, 6B, D, 
HWN, S, T, TJ, TN, and SS2B 

Naphthylamine Blue Black B, and 
B 


5 
Hat Black, all brands 
Radio Red G (Cassella) 
Wool Red B (Cassella) 
Alizarin Cyanol Red B (Cassella) 
Alizarin Direct Red BB (Badische) 
Alizarine Cyanol Green Blue B 
(Cassella) 
Neutral Wool Black B and.G (Cas- 
sella) 


Alphanol Black BG (Cassella) 


416 ACETATE SILK | 


Also see the list of acid and mordant dyes in Chapter XII. 

Frequently in dyeing woolen materials containing an acetate : 
silk thread effect, where a colored thread is desired the acetate 
silk is dyed before making up the fabric. While this previous — 
dyeing is not always necessary, especially in the case of cotton ; 
materials with an acetate silk thread effect, it is frequently desir-— 
able in the case of contrasting color thread effects in wool, so as to ~ 
avoid staining the wool with the acetate silk dyes. 

Several companies are marketing a selected line, of wool dyes { 
for use on wool in the presence of acetate silk. These are usually — 
simply a specially selected line of acid dyes which do not stain 
acetate silk and which are applicable to the wool at low tempera- | 
tures from a neutral or only slightly acid dye bath. 


The Kaline Dyes 


The Kaline dyes of the L. B. Holliday Company probably be- 
long to this class. They are applicable to wool at low tempera-— 
tures and do not stain acetate silk. They are of good strength, — 
as compared with other acid dyes, have good leveling properties, 
brilliancy of tone, and all general fastness. The following colors — 
are available: Kaline Yellow T, Kaline Orange D, Kaline Scarlet 
L and LG, Kaline Helio P, Kaline Sky Blue C, Kaline Blue M, 
Kaline Bright Blue A, Kaline Bright Violet P and R, and Kaline 
Red G. A good shade of brown may be obtained by combining 
1 part of Blue M, 4 parts of Red G, and 4 parts of Yellow T. A 
good shade of dark blue on wool may be obtained with 1.5 per 
cent of Helio P, 1.2 per cent of Blue M, and 0.5 per cent of 
Yellow T. They are applied by Method No. 109. When used 
with the dispersol dyes, it is usually best to dye the wool last. 

Method No. 109: Kaline Dyes on Wool with White Acetate 
Silk Effects. The goods should be scoured, rinsed and soured as 
in Method No. 6. For a1 to 3 per cent dyeing the dye bath is 
prepared with 10 per cent of Glauber’s salt crystals and 3 per cent 
of sulfuric acid. Enter the goods cold, raise the temperature to 
75 or 80° C. (167 or 176° F.) and continue the dyeing for three- 
quarters to one hour. Finally wash off in cold water and dry at 
a low temperature. 


TRUE SILK COMBINATIONS 41” 


The Gyco Neutral CW Dyes 


Under the above brand the Geigy Company offer a very inter- 
esting line of wool and true silk dyes for use on materials con- 
taining acetate silk. These dyes do not stain the acetate silk and 
may therefore be used where white acetate silk effects are desired. 
They may also be used with the Setacyl Direct or Art Silk CW 
dyes, by the one-bath method, where multi-colored effects are de- 
sired. The following colors are available: Gyco Neutral Orange 
CWM, Gyco Neutral Green YCW, Gyco Neutral Green CWB, 
Gyco Neutral Blue CWL, Gyco Neutral Red GCW, Gyco Neutral 
Yellow CWH, Gyco Neutral Red CWM, and Gyco Neutral Navy 
Blue CW. They are applied by Method No. 110, which is also 
suitable for the application of their Art Silk CW dyes. 

Method No. 110: Gyco Neutral Dyes on Wool or True Silk to 
Leave Acetate Silk Unstained. Dye in the same manner as in 
applying the direct cotton dyes to leave true silk white. Prepare 
the dye bath with the proper quantity of dyestuff and 10 to 20 
per cent of common salt. Enter the goods at 38° C. (100° F.) 
raise the temperature slowly to 71° C. (160° F.) and run at this 

temperature for from 20 to 30 minutes. 


Neolan Dyes on Acetate Silk Effects 

The Neolan dyes of the Ciba Company are a new class of 
dyestuffs in which the dye proper is combined with a metal, 
usually chromium, to form a water-soluble salt. The Neolan 
dyes are generally applied to wool in an acid dye bath with sulfuric 
acid, frequently using more acid than for the ordinary acid dye- 
stuff. For this reason, as a class, they are not as well suited for 
use on acetate silk-wool unions as some of the neutral dyeing acid 
and union dyes. On pure woolen materials they give very pleas- 
ing results. 

Three Fiber Combinations 

Dort® gives the following examples of three color combinations 

upon acetate silk, wool, and cotton. 


No. WC-1: Celanese-Greenish, Cotton-Brown, Wool-Blue 
2.4% S.R.A. Blue IV paste 
0.6% S.R.A. Golden Yellow IX paste 


418 ACETATE Sia 


4.0% C.R. Cotton Fast Brown R 
1 gram per liter of olive oil soap 
2cc. per liter of Turkey-red oil 

30 % Glauber’s salt. Rinse and then 
0.33% C.R. Wool Blue A and 
3.0% Formic acid. 


No. WC-2: Celanese—Blue Black, Cotton—Black, Wool—Red 
6.0% C.R. Cotton Fast Black B 
0.4% S.R.A. Blue IV paste 
0.2% S.R.A. Golden Yellow VIII paste 
1 gram per liter of olive oil soap 
2cc. per liter of Turkey-red oil 
30.0% Glauber’s salt. Rinse and then 
0.33% C.R. Wool Red 5B and 
3.0% Formic acid. 
No. WC-3: Celanese—Orange Red, Cotton—Blue, Wool— 
Violet 
2.0% C.R. Cotton Fast Blue FFB 
1.0% S.R.A. Orange II paste 
0.5% S.R.A. Red I paste 
1 gram per liter olive oil soap 
2 cc. per liter Turkey-red oil 
0.2% C.R. Wool Violet 10B 
0.066% C.R. Wool Red 5B and oe 
3.0% Formic Acid 


To leave the acetate silk white in acetate silk-true silk-cotton 
unions, the true silk should be dyed with acid dyes and acetic acid. 
Rinse well and neutralize the goods with sodium bicarbonate. 
Then dye the cotton with suitable direct cotton dyes. This method 
may be reversed when a direct dye which does not stain true 
silk is used. Some direct dyes such as Chrysophenine and Ben- 
zopurpurin give almost the same shade on both the true silk and 
cotton, in which case the one dyeing operation will answer for 
both fibers. 

Where three or four fiber combinations of acetate silk, cotton 
and/or rayon, wool, and/or true silk are to be dyed, it is fre- 
quently possible, by a suitable selection of union dyes to cover the 
cotton, older rayon, wool, and silk in the union dye bath ; however, 
in this case it is usually almost impossible to get an exact match 


TRUE SILK COMBINATIONS 419 


to sample of the shade on all of the fibers, or to obtain a solid 
shade. If exact matches are desired, it is generally much better 
to dye each fiber in a separate bath with a dyestuff which stains 
the accompanying fibers just as little as possible. Even then it 
is frequently difficult to get the desired result as regards to fast- 
ness, etc., in every case. 

Kay® says that three color effects on mixtures of acetate silk, 
cotton or regenerated cellulose rayon, and wool may be obtained 
by either the one- or two-bath method, but that where it is de- 
sired to avoid staining the wool, the two-bath process should be 
used. In some cases, as where the wool is to be dyed a dull shade, 
some staining of the wool may not be objectionable and the one- 
bath process may be used. In general, a suitable ground shade is 
usually dyed on the wool first and the brighter contrasting colors 
applied to the cotton or older rayon and acetate silk. He recom- 
mends such shades as fawns, tans, drabs, dull greens, slates, and 
browns for the ground-work; while shades of lilac, apricot, 
lemon, pink, or saxe are used as contrasting colors. 

He mentions that the selection of suitable dyestuffs is of course 
one of the most important elements for the success of this process ; 
and for the wool, only neutral-dyeing dyestuffs which are applic- 
able at low temperatures, with a minimum of staining of the 
other fibers, should be used. The cotton should be dyed with 
acetate silk-white dyestuffs which have no affinity for wool. For 
the acetate silk, dispersol dyes with a minimum affinity for the 
other fibers should be used. He suggests the following as suit- 
able for use in this manner : 


Wool Cotton Acetate Silk 
Coomassie Navy Blue 2RNX Chlorazol Fast Orange D Duranol Orange G_ paste 
ie i * GNX CR Chlorazol Sky Blue FF a Red G paste 
He Fast Black B a ue Yellow GX ss <*" 28 spaste 
4g Milling Scarlet G “ oa Violet R SS Blue G paste 
Disulphine Green B mo ie Fast Eosine B re Violet 2R paste 
ss Blue A od a “© Pink BK Dispersol Yellow 3G 


The scoured and rinsed goods are entered into the 20 or 30 to 
1 dye bath at, say, 40° C. (104° F.), the temperature raised to 
80 or 85° C. (176 or 185° F.), and the dyeing continued for a 
half hour in the presence of 10 or 20 per cent of salt. The goods 
are then rinsed thoroughly, or may be soaped in a bath containing 


420 ACETATE Site 


1 or 2 parts per thousand of olive oil soap. The two-bath method 
is similar to the above, but the cotton is dyed in a second bath. 
In order to reduce the staining of the wool to a minimum, the 
temperature of this bath may be limited to about 30° C. (86° F.). 


Katanol in Union Dyeing 


The restraining influence of Katanol W (sulfurized phenol) 
on the affinity of certain dyestuffs for animal fibers (both true 
silk and wool) is of considerable value in dyeing these fibers in 
combination with cotton or the older rayons, and is therefore of 
interest in obtaining multicolor effects on goods containing acetate 
silk. In using this compound in dyeing cotton-wool unions, the 
wool is dyed to shade first at a high temperature in the usual 
manner. The dye bath is then cooled to 75 or 80° C. (16% or 
176° F.), 3 per cent of Katanol W added, and the cotton allowed 
to absorb color until the desired shade is obtained, there being 
no simultaneous change in the shade of the wool. 

It should be noted that in dyeing solid colors on half-wool or 
half-true-silk goods the Katanol should not be added to the dye 
bath at the start, as in some cases it also retards the absorption of 
certain acid dyes which have an affinity for wool in a neutral dye 
bath. It has been recommended to dye the cotton in acid-dyed 
wool unions with substantive dyes at 75 to 80° C. in the presence 
of Katanol, instead of by the usual method at 30° C. (87° F.) 
in the presence of sodium carbonate, as the Katanol method 
gives cotton colors faster to rubbing, the wool is less stained, 
and its damage by the alkaline dye bath is avoided; also better 
exhaustion of the dye bath is obtained. Katanol W is also useful 
in dyeing true silk-cotton materials, but in this case the true silk 
resists the direct dyes better when premordanted for an hour 
at 80 to 90° C. (176 to 194° F.) with 8 or 10 per cent of Katanol 
W and 8 or 4 per cent of formic acid. 

As an example of a white acetate silk effect in a blue and red 
dyed cotton-wool-acetate silk combination,® the wool may be dyed 
blue with an acid dyestuff from an acid bath, and the cotton with 
a red direct cotton dye at 50° C. (122° F.) in the presence of 3 
per cent of Katanol W (to retard the direct dye on the wool), 
leaving the acetate silk white. 


TRUE SILK COMBINATIONS 421 


A three-color effect on a similar fabric can be obtained by 
first dyeing the acetate silk with Cellit Fast Yellow 2GN, diazo- 
tizing and developing a red shade, as in Methods No. 68, No. 
68-A and No. 68-B. This leaves the cotton practically white but 
the wool is stained yellow. The wool is then dyed blue with an 
acid dyestuff, the fabric thoroughly washed and the cotton dyed 
green or olive with a direct cotton dye in the presence Katanol W. 

A four-color effect on an acetae silk-cotton-wool-true silk 
combination is possible by first dyeing the acetate silk as de- 
scribed above, then dyeing the wool and true silk in the one dye 
bath with dyes having different affinities for wool and true silk 
under different conditions, such as Patent Blue and Tartrazine. 
In this case the true silk may be dyed a deep peacock blue in 30 
to 45 minutes at a low temperature, while on adding sulfuric 
acid and raising the temperature to 100° C. (212° F.) the wool 
is dyed a Russian Green. The cotton is subsequently dyed a violet 
color with a direct cotton dye, in the presence of Katanol W, 
pire (ive I .). 

Three-color effects can also be obtained on acetate silk-cotton- 
viscose, or acetate silk-cotton-mercerized cotton fabrics by pre- 
viously dyeing the cotton black, when in the yarn, and afterwards 
dyeing the acetate silk and viscose or mercerized cotton in dif- 
ferent colors by the usual methods. 

Another method of obtaining three-color effects on acetate silk- 
cotton-true silk goods is to dye both the acetate silk and cotton 
or older rayon in one dye bath with suitable dispersol and direct 
cotton dyes, in the presence of 2 or 3 grams per liter of olive oil 
soap and Katanol W. The bath is first prepared with the dis- 
persol dye and the soap, if desired. After dyeing, for a half to 
one hour at 50 to 70° C. (122 to 158° F.), or when the dispersol 
dyestuff is about exhausted from the bath, 3 or 4 grams per liter 
of Katanol and about half of the direct dyestuff may be added to 
the bath. When the direct dyestuff is no longer feeding onto 
‘ the cotton, 5 to 20 per cent of Glauber’s salt may be added. When 
the cotton comes up to shade, the goods are rinsed and the true 
silk is dyed with acid dyestuffs in a fresh warm dye bath in the 
presence of acetic acid. , | 


422 ACETATE SILK 


This process appears to be covered by German Patent No. 
432,111 to the I. G. Farbenindustrie A.-G., which states that the 
affinity of wool for acid and neutral dyestate may be removed ~ 
or deminished by treating the fiber, before or during the dyeing, — 
with a sulfurized phenol, with or without the addition of tin salts. 

Also see British Patent No. 262,506. ' 


References 


1R. G. Dort, Chemicals 25, No. 1, 25 (1926). 

*Green and Saunders, J. Soe. Dyers and Colourists 39, 14 (1923). 
SRG, Dor, Chemicals 25, No. 1, 39 (1926)° 

*G. Rudolph, Textilber 7, 88 (192 ae 

®°G. Rudolph,. Kunsteide 8, 13-5 (1926). 

®°H. Kay. Dyer and Calico Printer 56, 25 (1926). 


CHAPTER XXXV 


CLEARING ACETATE SILK UNIONS AND STRIPPING 
Pei TATE SILK 


Tue methods used in clearing the various fibers in acetate silk 
unions are very similar to those used in clearing the fibers in 
dyeing other unions, such as soaping in a neutral or alkaline bath, 
a light bleach, etc. 

Method No. 111: Clearing the Cotton or Older Rayon in 
Acetate Silk Unions. After dyeing the acetate silk, the accom- 
panying fiber may be cleared by means of a hot or cold washout 
with dilute acetic acid. This method is particularly useful in the 
cotton in basic dyed Lustron-cotton unions. Lactic acid may be 
substituted for the acetic acid. 

Method No. 112: Clearing the Cotton or Older Rayon in Ace- 
tate Silk Unions. After dyeing, the union may be treated in a 
bath containing 1.25 gram per liter of olive oil soap at 45° C. 
(113° F.). In many cases it is of advantage to proceed this 
treatment by Method No. 111. Sometimes a second soaping at 
49 to 71° C. (120 to 160° F.) for about 5 minutes is advantageous. 

Method No. 113: Clearing the Cotton or Older Rayon in Ace- 
tate Silk Unions. In some cases where one or two warm acetic 
acid treatments, as in Method No. 111, does not clear the cotton, 
it may be given a final treatment in a bath containing about one 
per cent of sodium bicarbonate (baking soda) and one per cent 
of soap, on the weight of the goods, for fifteen minutes at 45° C. 
pia’ F.). 

Method No. 114: Clearing the Cotton or Older Rayon in Ace- 
tate Silk Unions. Where necessary, the union may be given a 
mild cold bleach, similar to Method No. 15,2 but only about half 
this strength, after soaping as in Methods No. 112 or No. 113. 
A combination soap and bleach treatment, as given in Method 
No. 17 may also be used. 


®"See Chapter No. IX. 
423 


424 ACETATE SILK 


Method No. 115: Clearing Cellit Stained Cotton or Viscose. 
This is best accomplished by soaping twice at 49 to 71° C. (120 
to 160° F.) for about 5 minutes. This is claimed to leave the 
interwoven cotton practically white. 

Method No. 116: Clearing the Acetate Silk in Sulfur-Dyed 
Acetate Silk-Cotton Unions. Where it is desired to leave the ace- 


1 


: 
3 
/ 
4 
a 
: 
: 
| 


tate silk white in the presence of sulfur-dyed cotton in unions, — 


an after-treatment with a dilute hydrosulfite solution, slightly 
alkaline with ammonia, is usually of considerable assistance. 
Method No. 117: Clearing the Cotton or Older Rayons in Dis- 
persol-Dyed Acetate Silk Unions. In cases where the cotton or 
older rayons are stained by the dispersol dyes, such as 5.R.A. 
Orange I, S.R.A. Red I, S.R.A. Red III, or S.R.A. Red V, the 


3 
q 
‘4 
' 
4 
, 


cotton may be cleared by bleaching in a soap bath containing 1_ 
gram of sodium hydrosulfite and 0.2 gram of sodium carbonate, — 
per liter. Where this bleaching process is to be used on the cotton 
or older rayon, the acetate silk should be dyed a slightly deeper 


shade to allow for the stripping effect of this bleach. 


Stripping Acetate Silk 


As might be inferred from the high affinity of many of the 


basic groups, particularly the amino group, for acetate silk and the 
discussion of discharge printing in Chapter XXIV, it is not always 
easy to strip properly dyed acetate silk. While some of the older 
dyestuffs are not difficult to strip, most of the special acetate silk 
dyes resists stripping quite well. 

As a class, the dispersol dyes do not usually strip very easily, 
but in cases where the shade has just been dyed unevenly or a 
little too heavy, they can often be sufficiently stripped by working 
the goods in a fresh bath prepared with soap and Turkey-red oil, 
or even a little soda ash at 80° C. (176° F.), as in Method No. 
118. Where the dyes have not been solubilized by means of 
soapy baths, the addition of the solubilizing agent used in the 
preparation of the dispersol paste may considerably aid the strip- 
ping process. It has been suggested to add hydrosulfite to the 
soapy bath mentioned above. The formaldehyde-sulfoxylates, 
acidified with formic acid, have also been used at 80° C. for 
stripping acetate silk. 


CLEARING UNIONS AND STRIPPING 425 


S.R.A. dyed Celanese may usually be stripped sufficiently for 
redyeing by Method No. 118, but where this is not sufficient, the 
goods may be given a bleach as in Method No. 119. This 
usually gives a pale level yellow or white ground. After the 
stripping treatment, the goods should be soaped in a bath con- 
taining 2 cubic centimeters per liter of Turkey-red oil. The same 
stripping operations may be used on Celanese-cotton unions as on 
Celanese, but Method No. 119 should not be used on materials 
containing wool or true silk, as these do not withstand the action 
of the hypochlorite very well. In this case a peroxide or per- 
manganate bleach, as given in Methods No. 19 or No. 20, may 
be used. 

Method No. 118: Stripping Celanese. Work the goods for 30 
to 45 minutes at 75° C. (167° F.) in a bath each liter of which 
contains 2.5 grams of olive oil soap or the equivalent of Turkey- 
red oil, 0.5 gram of sodium hydroxide, 5 grams of sodium hydro- 
sulfite, and 1 cubic centimeter of ammonia. Rinse well. 

Method No. 119: Stripping Celanese. Work the goods for 30 
minutes or longer in a 0.25° Tw. sodium hypochlorite bath which 
is just acid With hydrochloric acid. Rinse well and give an 
antichlor treatment at 60° C. (140° F.) with sodium bisulfite or 
thiosulfate, as in Method No. 18. 


»See Chapter IX. 


CHAPTER XXXVI 
THE MODE OF APPLICATION 


As in dyeing any other fiber, there is no one type of apparatus 
or machine particularly adapted to dyeing acetate silk in any 
one form and many varieties of apparatus have been used suc- 
cessfully under different conditions. For this reason it is im- 
possible to specify definite makes of apparatus. As in all other 
dyeing, each style or type of machine has its own particular ad- 
vantages and disadvantages. No matter in what form it is dyed 
or what type of apparatus is used, one particular fact must be kept 
in mind, and that is that this fiber must be handled in much the 
same manner as true silk, rather than like cotton. 

If the skeins are on sticks, they must be extremely smooth, and 
not the rough wooden variety frequently used in cotton dyeing. 
In machine dyeing the same care must be exercised to avoid injury 
to either the yarn or whatever other form the goods may be in. 
In fact this point is very important in handling any variety of 
rayon. On account of the superior strength of acetate silk when 
wet, it has some advantages in dyeing over some of the older 
products, but on account of this very water resistance, stronger 
solutions and shorter dye baths must be used on acetate silk than 
on the older rayons. 

Greenhalgh says that at the present time the dyeing of acetate 
silk in the form of yarn is quite as simple, in the manner of 
operation, as the dyeing of viscose. The usual care must be ob- 
served in handling the yarn, especially in the case of fine counts, 
and under suitable conditions no difficulty should arise. Hank 
yarns, such as Celfect and Celvis, may be dyed in the usual manner 
by the ordinary hand and stick method, or on any of the well- 
known yarn dyeing machines with equal facility. 

Methods of dyeing under pressure, similar to those widely 
used on cotton in the form of cones, tubes, cheeses, beams, etc., 
have not as yet found much application for acetate silk and may 


426 


Peep reOr APPLICATION 427 


require some study before entire satisfaction is obtained. They 
would probably give much less difficulty where white acetate silk 
effects are desired. 

Hosiery and other knit goods may be dyed either in the open 
beck, on sticks, or in net bags in paddle or drum machines. As 
usual in hosiery dyeing, the principal difficulty is in properly 
penetrating the seams. Without doubt the addition of suitable 
leveling agents, such as Celascour, Turkey-red oil, sodium pheno- 
late, etc., may be of considerable assistance in this direction. 
Knitted fabrics are dyed by the usual method in rope form in a 
winch machine, after the customary stitching together. 

In dyeing acetate silk piece goods, both the reel and winch 
have given good results. In the winch, when the fabric is loose 
in the dye bath, the use of Celascour or a similar material is of 
assistance. The dye bath itself should be of wood, enameled 
ware, monel metal, or copper, except for diazotizing, where copper 
should not be used. 

The dispersol dyes are usually applied to piece goods in the 
winch or jig, and in the hank by hand or on machines of the 
ordinary type, no special machinery being required. 


CHAPTER XXXVII 
DYEING TROUBLES AND FAULTS 


Jusr as in dyeing all other fibers, the dyer is going to encounter 
many troubles and “kicks” in dyeing acetate silk, generally all the 
more so at the start, as it is usually a new fiber to the manufac- 
turer, dyer, and the customer. However the experienced dyer has 
all of his accumulated experienc in dyeing the older fibers, rayons 
included, to use as a foundation and store-house of experience, 
so that these troubles need not prove insurmountable. Again, as 
in dyeing all other fibers, these kicks are not always the fault of 
the dyer but it is usually up to him to find the true cause. For 
instance, according to the Dyer and Calico Printer 55, 120 (1926), 
varying humidity conditions during the winding and weaving of 
viscose and acetate silk yarns produce yarns of uneven denier 
and varying dyeing properties, since the moisture content of the 
rayon has a considerable influence on its extensibility under tensile 
strain. For example, viscose yarn at 45 per cent relative humidity 
stretches 13.5 per cent and then breaks under a load of 44 pounds, 
whereas similar yarn at 85 per cent humidity stretches 19 per 
cent and breaks under a load of only 35 pounds. Acetate, silk 
yarn is affected similarly but to a less extent. 

It is usually true that everything is blamed on the dyer, whether 
he is at fault or not, so that he may expect all kinds of complaints 
regarding acetate silk materials which come out of the dye bath 
uneven shades. While this may be the fault of the dyer, again it 
may be due to a fault in the original acetate silk, or it may very 
easily be due to a fault in the previous handling of the acetate 
silk or the goods containing it. As pointed out under the saponifi- 
cation process of dyeing, it is very easy to cause a partial hydroly- 
sis or saponification of the acetate silk in either an alkaline or 
acid bath. 

The defect in this accidentally hydrolyzed fiber is usually very 
uneven, and in dyeing it is liable to give all varieties of shades in 


428 


DYEING TROUBLES AND FAULTS 429 


the one dye bath. This defect is particularly noticeable when the 
special acetate silk dyes are being used. With members of the 
acid or basic groups or other of the older dyes which are applicable 
to both cotton and acetate silk, the defect will be far less obvious. 
With the dispersol type and Ionamine dyes, the badly hydrolyzed 
portions of the fiber may be almost or practically unstained, while 
the normal parts of the fiber are colored a deep shade in the same 
dye bath. While the basic dyes give a deep shade on the normal 
parts of Lustron, the hydrolyzed portions are dyed even darker. 
The direct dyes do not usually dye the normal fiber but give good 
shades on the hydrolyzed portions of both Lustron, Celanese, 
and Rhodiaseta. 

It should also be remembered, as pointed out in connection with 
the preparation of cellulose acetate, that it is exceedingly difficult to 
prepare an absolute uniform cellulose acetate from day to day, 
or even from batch to batch. Of course uneven material means 
fiber varying in its dyeing properties. This is sometimes the cause 
of unevenness in dyeing, but this cause is not confined to acetate 
silk alone as it is found in all other rayons to some extent. Some 
years ago this difficulty was much more prevalent than it is today, 
and undoubtedly with the advances in control and manufacturing 
methods, this fault will become even less common. 

It is important to note that in dyeing any type of rayon, acetate 
included, the best results are obtained only by slowly building up 
the color on the fiber by small successive additions of dyestuff to 
the dye bath as the exhaustion proceeds. This point is particularly 
important in dyeing more or less contrasting colors or white 
effects on combinations of two or more varieties of rayon, such 
as viscose and acetate, or unions containing natural fibers and 
rayon. 

In all such cases, with any variety of rayon, the color on the 
fiber should be built up, layer on layer. Thus, for example, a dye- 
ing may be started with say 8 ounces of dyestuff in the dye bath 
so as to give after 15 minutes at 30° C. (86° F.) a shade corre- 
sponding to 18 to 25 per cent of the desired shade. An addition 
of, say 1 ounce of dyestuff, together with a similar period of time 
at a temperature of 45° C. (113° F.), may give approximately 


430 ACETATE SILK 


50 or 60 per cent of the desired shade, which may then be further 
increased by future additions of dyestuff or a proper manipulation 
of the temperature of the dye bath. In this way it is possible to 
obtain much more level results on all varieties of rayons as well 
as to secure the desired white effects on unions under the proper 
conditions. 

Any toning or shading which may be necessary on the rayon, 
except that necessary for final matching to sample, should be done 
in the early stages of the dyeing, instead of at the end as is usually 
done on wool and cotton. In this way an absolutely solid founda- 
tion tone is obtained which appears to be of considerable advantage 
in the case of the rayons, all of which are more transparent than 
the natural fibers, cotton and wool. Proper attention to this detail 
may avoid difficulties due to apparent two-color effects when the 
dyed rayon is viewed from different angles. This is usually caused 
by the shading dyes being entirely on the surface of the fiber, as iS 
frequently the case when it is added in the final stage of the dye- 
ing. An example of this latter defect mentioned by Greenhalgh? 
is the green shade produced on acetate silk by p-nitroaniline in the 
presence of hydrochloric acid, finally topped with Capri Blue in a 
fresh bath containing hydrochloric acid. While it is true that a 
green shade is obtained by this process, the tone varies from 
yellow to blue according to the angle from which it is viewed. 

As in the application of simple shades on other fibers, the appli- 
cation of self shades to acetate silk is much simpler than that of 
compound shades, especially where the dyer is endeavoring to dye 
two or more fibers in a single dye bath. In applying compound 
shades to any fiber, acetate silk or otherwise, the dyer should have 
a full and complete knowledge of each component dye of the 
mixture, its affinity for the fiber at various temperatures, the effect 
of the numerous variables likely to occur in the dye bath, etc. 
Only in this way can compound shades be handled with satisfac- 
tion on any fiber, and as the dyer is generally dealing with dye- 
stuffs and methods which are more or less new to him in con- 
nection with acetate silk, particular care should be taken to make 
a proper study of the dyestuffs, etc., before attempting operations 
on a larger scale. 


DYEING TROUBLES AND FAULTS 431 


The fault in dyed goods known as “dye veining” or “dye river- 
ing,’ terms which are practically self-explanatory, is particularly 
common inrayon. This fault may be caused by creasing or crack- 
ing the rayon during the weaving or knitting process, or by scour- 
ing at too low a temperature and with too short a scouring bath. 
Greenhalgh? states that the trouble is usually largely overcome by 
scouring at 75 to 85° C. (167 to 185° F.) and subsequently utiliz- 
ing this bath for the dyeing functions at the same temperature. 
While this method of combating this trouble may not be applicable 
to all methods of dyeing acetate silk, as, for instance, in applying 
the basic dyes with salt or acetic acid, it undoubtedly will be found 
useful in dyeing the older rayons in acetate silk combinations. 


References 


*E. Greenhalgh, Dyer and Calico Printer 55, 191 (1926). 
?E. Greenhalgh, Dyer and Calico Printer 55, 147 (1926). 


CHAPTER XXXVIII 
SIZING AND FINISHING ACETATE SILK 


WHILE sizing and finishing are usually distinct processes, espe- 
cially on rayon, they are frequently considered together. In~ 
weaving the rayons, usually only the warps are sized, in order to 
lubricate and strengthen them, while the filling is seldom sized. 
For knitting purposes, the rayon is usually only oiled. In the case 
of the older regenerated cellulose rayons, the sizing mixture usu- 
ally contains some constituent to reduce the hygroscopic properties 
of the rayon, and thus, by reducing their regain, maintain their 
tensile strength and normal resistance to stretching to a greater 
extent at the usual high humidity of the weaving room. 

In weaving acetate silk this latter function (reduction of re- 
gain) is entirely unnecessary in the sizing, for while the older 
rayons handle best at comparatively low relative humidities, 1.€., 
below about 70 per cent, acetate silk, probably on account of its 
water resistance and normally low regain, requires a higher 
humidity to prevent it from being brittle and breaking in process. 
This factor should be an advantage in using acetate silk, as com- 
pared with the older rayons, in connection with wool and true silk. 

In weaving fabrics containing acetate silk it is important that 
as little tension as possible be placed on the fiber, on account of 
its elasticity. If care is not used in this direction the fabric may 
finish up with the rayon too short or under tension. For this 
reason a good strengthening and lubricating size is the principal 
need in handling acetate silk. As a lubricant, it has been recom- 
mended! to use an emulsion of equal parts of olive and sulfonated 
or soluble oil on acetate silk in process of manufacture. 

Grimshaw? has investigated the sizing, sizes for, and removal 
of size from acetate silk, and points out that, as might be expected, 
due to its different composition, acetate silk presents difficulties 
in sizing that are not found in connection with cotton or the older 
rayons. His experiments indicate that acetate silk may be sized 


432 


SIZING AND FINISHING 433 


_ better in a special slasher than in the skein. In these experiments 
he divides the various sizes into groups according to the method 
of preparation. The following is a summary of the results. 


Group No. I 


General Method of Preparation. Soak the materials given in 
following formulas well with cold water, gradually heat to the 
boil, and cook for one hour until well pasted. Then make up to 
volume with water before using. Cool to 38° C. (100° F.), dip 
the skeins, squeeze well, run through the wringer, and dry in the 
ets 3. ¢ 


Formula 


No. 1: Forty fluidity corn starch 3.5, pearl starch 1.5, and 
water 125. 

No. 2: Forty fluidity corn starch 1.5, pearl starch 3.5, and 
water 125. 

No. 3: Same as No. 1, plus 2 parts of softener. 

No. 1%: Forty fluidity corn starch 5, water 125., 

No. 19: Seventy-five fluidity corn starch 5, water 125. 

No. 21: Gelatin 1, glucose 1, softener 1, fifty fluidity corn 
starch 5,.and water 125. 

No number: Fifty fluidity corn starch 5, water 125. 


Group No. 2 


General Method of Preparation. Soak the materials given in 
the formula over night in water. Boil 15 minutes (straining in 
the case of Irish moss) and make up to volume. Apply as in 

mroup No, 1, 4.2., at 38° C. 


Formula 


No. 6: Gelatin 2, water 200. 

No. %: K Gum 5, water 200. 

No. 8: Gum tragasol 8, water 200. 
No number: Irish moss 10, water 200. 


Group No. 3 
General Method of Preparation. Boil 30 minutes, bring up to 
volume, cool, and apply as above 


434 ACETATE SILK 


Formula 


No. 9: Soluble potato starch 5, water 100. 

No. 10: Potato starch 5, water 100. 

No. 11: Jelly glaze 1, water 32. 

No. 12: Yellow dextrin 5, water 100. 

No. 13: White dextrin 5, water 100. 

No. 15: Amidex 5, water 100. 

No number: Corn starch 9.5, Arcy 0.5, water 2950. 

The regular Celanese size, as supplied by the manufacturers, 
was applied at 60° C. (140° F.) ina 1 to 3 dilution. 


After drying the sizes were graded into classes according to the 
various properties, as shown by the sized skeins, such as softness, 
appearance, etc. In each case Class No. 1 is the best, No. 2 next 


to the best, etc. 


Grading for Appearance 


Class No. 1 (Best) 
K gum, 
Gum tragasol, 
White dextrin, 
Amidex, 
Irish moss. 


Class No. 2 (Good) 
Formula No. 3, 
Soluble potato starch, 
Potato starch, 
Kasagra gum, 


1% gelatin, 
Corn starch plus Arcy, 
Formula No. 21. 


Class No. 3 (Fair) 
Formula No. 1, 
Formula No. 2, 
Yellow dextrin, 
Celanese size, 
Forty fluidity corn starch, 
Jelly size. 


Grading for Softness 


Class No. 1 (Best) 


Formula No. 3, 
K gum, 
Amidex. 


Class No. 2 (Good) 


Soluble potato starch, 
Potato starch, 

Yellow dextrin, 

White dextrin, 
Kasagra gum, 

Gelatin, 

Corn starch plus Arcy, 


Formula No. 21. 


Class No. 3 (Fair) 


Formula No. 1, 

Formula No. 2, 

Forty fluidity corn starch, 
Jelly glaze, 

Irish moss. 


Class No. 4 (Poor) 


Celanese size, 
Fifty fluidity corn starch, 
Seventy-five fluidity corn starch. 


SIZING AND FINISHING 435 


Grading for Binding Properties under the Pick Glass 


Class No. 1 (Best) Forty fluidity corn starch, 
Formula No. 1, Jelly glaze, 

Gelatin, Forty fluidity corn starch, 
Celanese size, Seventy-five fluidity corn starch, 
Corn starch plus Arcy. Formula 21, 

Irish moss. 

Class No. 2 (Good) f 
Formula No. 2. Class No. Ss (Fair) 
Formula No. 3, K gum, : 

Soluble potato starch, White dextrin. 


Potato starch, 


Grading by Pulling the Sized and Dried Yarn over the Thumb 
Nail for Separation or Breakage 


Class No. 1 (Best) Class No. 3 (Fair) 
Formula No. 1, K gum, 
Formula No. 2, Gum tragasol, 
Fifty fluidity corn starch, Yellow dextrin, 
Seventy-five fluidity corn starch, Kasagra gum, 
Formula No. 21. Irish moss, 

Class No. 2 (Good) VEEN ees 
Formula No. 3 Class No. 4 (Poor) 
Gelatin, Soluble potato starch, 
Celanese size, White dextrin, 
Forty fluidity corn starch, Amidex. 


Corn starch plus Arcy, 
Jelly glaze. 

Weighing the sized skeins showed that they retained the follow- 
ing quantities of size, based upon the weight of the original skein: 
Celanese size, 10.21 per cent; gelatin, 4.29 per cent; potato 
Starch, 4.84 per cent; 75 fluidity corn starch, 5.37 per cent; 
formula No. 21, 5.3% per cent; formula No. 1, 5.91 per cent; 
and formula No. 3, 3.17 per cent. 


Patents On Sizing Mixtures 


British Patent No. 244,947, June 27, 1924, to British Celanese, 
Ltd., C. F. Ryley and G. A. Awcock, states that a sizing composi- 
tion suitable for use on Celanese, as well as other textile yarns, 
may be prepared from a water-insoluble soap of resin acids or 
naphthenic acids and one or more lubricating agents, such as non- 
volatile, non-drying oils, fats, waxes, or liquid or solid fatty acids 
together with one or more resins, as dammar resin or gum mastic. 


436 ACETATE SILK 


One or more soaps of fatty acids, including those of sodium, 
potassium, ammonium, but preferably those of calcium, mag- 
nesium, zinc, or aluminum may be added. The resin may be dis- 
solved in an indifferent solvent such as benzene, toluene, xylene, 
or turpentine, etc., with admixture of the lubricating agent and 
other constituents; or emulsifying agents may be used; or the 
materials may be melted together. 

For example, gum mastic or dammar resin is used in the pro- 
portion of 20 parts by weight, with lard 7 parts, and xylene 26 
parts, with or without 1.5 parts of magnesium oleate. Or calcium 
resinate 20, lard 9, and benzene 25, with or without zinc oleate 
2 parts. About 5 or 10 per cent of size on the weight of the yarn 
is generally used and may be applied by dipping the hanks or dur- 
ing the winding. In the case of threads prepared by the dry spin- 
ning method, as in British Patent No. 210,266, it may be applied 
continuously during their production. The sized product is not 
brittle, dusty, or sticky. The size may be removed by soap scour- 
ing, with or without previous acid treatment. 

British Patent No. 247,979, June 27, 1924, to the same in- 
ventors, covers a sizing composition suitable for Celanese and 
other textile yarns, consisting of a mixture of one or more lubri- 
cating agents, such as non-drying oils, fats, waxes, or liquid or 
solid fatty acids, with one or more resins such as gum mastic or 
dammar resin, which will form a non-sticky film. Drying oils or 
colophony should not be used. The ingredients may be dissolved 
in an indifferent solvent, such as benzene, toluene, xylene, or tur- 
pentine, and the solution applied to the yarn. The sized yarn is 
not brittle, dusty, or sticky. Soap of the fatty acids may be added 
and those of sodium, potassium, ammonium, calcium, magnesium 
zinc, aluminum, etc., are mentioned. 

The removal of sizing materials was discussed in Chapter IX, 
in connection with scouring. 


Finishing Acetate Silk Goods 
As in all other finishing, the proper finishing of acetate silk 
fabrics, knit goods, etc., is an art in itself about which very little 
has been written in comparison to its importance. In any finish- 


»IZING AND FINISHING 437 


ing operation, the mechanical processes, type of equipment, formu- 
las, and materials used must be governed entirely by the goods 
being handled, the other fiber or fibers present, their condition, 
and the results or particular style of finish desired. The particu- 
lar chemical constitution of acetate silk, with its resulting in- 
dividual properties, frequently renders the finishing of this fiber 
in any form quite different from that of the older rayons or nat- 
ural fibers. However, the experience and formulas used in finish- 
ing the older rayons usually form the best basis for experiments in 
finishing acetate silk, if one always bears in mind the characteristic 
properties of the new fiber. Blackshaw* says that in many respects 
the finishing of acetate silk-cotton unions is very similar to that 
of the corresponding viscose-cotton materials, especially in regard 
to the mechanical end of the procedure. 

If drying may really be considered a finishing operation, it 1s 
usually the first one to be used on any class of goods. Yarns or 
loosely knit fabric? which are not liable to crease may be hydro- 
extracted in the ordinary rotating cage or drum machine. Closely 
knit or woven fabrics, such as taffetas, satins, etc., should be han- 
dled on the rotating cyclinder machine in such a manner that the 
goods are kept in open width. A suction machine, such as is used 
in handling true silk materials, is also useful for these fabrics, as 
well as crepes. Any squeezing operation is dangerous on account 
of creasing. 

Crease marks are rather difficult to remove from acetate silk or 
materials containing it‘ and for this reason should be avoided 
wherever possible. If they have been allowed to dry in the fabric, 
it should be rewet thoroughly and dried on the stenter. In sten- 
tering or in any other finishing operation on acetate silk, never 
stretch the goods to more than the gray goods width, otherwise the 
strength of the fabric may be impaired. With fabrics much better 
success is usually attained on the stenter than on cans, for while 
most acetate silks are delustered at temperatures above 85° C. 
(185° F.) in the presence of aqueous vapor, they withstand 100° 
C. (212° F.) in a dryer atmosphere without blinding; but at a 
somewhat higher temperature, such as in contact with a hot can, 
they appear to fuse and become glazed, or under extreme treat- 
ment, brittle. 


438 ACETATE:SIGk, 


In the burning test for acetate silk we have seen how this fiber 
tends to soften or even melt with increasing temperature. In 
finishing, this point must not be overlooked. A high temperature 
in finishing may result in a very high luster or glaze on the Cela- 
nese fiber or fabric, which may or may not be desired. Very high 
temperatures may cause the fiber to become plastic enough to stick 
to the calenders, etc. While this very glazing process is used in 
some finishing operations to some extent to secure a “hard candy” 
finish, it must be very carefully controlled to avoid a permanent 
injury to the fabric, and it should only be attempted as a separate 
operation, not as a part of drying. For this reason as low a tem- 
perature as practicable should be used in any drying operation on 
acetate silk or materials containing it. 

The manufacturers of Celanese recommend that after knit goods 
are dyed they be given a soft finish by running for 10 minutes in 
a bath containing 8 cubic centimeters per liter of olive oil emulsion, 
prepared by Formula No. 120. They should then be hydroex- 
tracted, without rinsing, and dried. For a “scroopy” finish on 
Celanese, prepare the bath with 4 cubic centimeters per liter of 
_ the olive oil emulsion and then acidify the bath with 1 cubic centi- 
meter per liter of 100 per cent acetic or formic acid, before enter- 
ing the goods. Tartaric acid may be substituted for the acids 
mentioned above. Celanese will withstand the usual alkaline 
emulsion finish, or an acid finish containing two cubic centimeters 
per liter of formic acid. Finishing materials for Lustron should 
be slightly on the alkaline side, preferably with sodium bicarbon- 
ate. 

Formula No. 120: Olive Oil Emulsion. The emulsion is pre- 
pared by stirring 1.68 kilos of 67° Tw. (1.335 sp. gr.) potassium 
hydroxide solution into 12 liters of good olive oil and allowing 
this to stand over night. It is then agitated well for about 40 
minutes, while adding 18 liters of boiling water. About 30 liters 
of cold water are then slowly added, while stirring, and the emul- 
sion is ready for use. This will keep for several days but should 
be well mixed or preferably boiled before use. 

Dort® describes a number of finishes for Celanese, probably 
some of which may be applicable to Rhodiaseta by the same proc- 


Se ee ae) Me te Uae ee Re aren 


Konaic4 


Fag. aA oe ee 


oars an 


ee ee ee a ee | 


SIZING AND FINISHING 439 


ess, while others may require more changes for use on Lustron. 
Celanese may be completely delustered and given a beautiful “egg- 
shell” finish by Method No. 121. Not only can the luster of Cela- 
nese be controlled to any degree between the very highest candy- 
like effect to the complete delustered or egg-shell finish, but the 
handle may also be varied considerably. A very soft handle is 
obtained by means of the olive oil emulsion given in Formula No. 
120. If a heavier handle and scroop are desired, this can be ob- 
tained by means of acetic, formic, or tartaric acid, the last named 
acid giving the harshest, crackly scroop and heaviest handle. An 
alpaca finish may be obtained on certain Celanese fabrics by the 
use of gum tragacanth and glue. A crepe finish may be obtained 
by treating for an hour at 80° C. (176° F.) in a bath containing 
olive oil soap and soda ash, and then boiling in a 30 per cent solu- 
tion of Glauber’s salt. 

Method No. 121: Delustering Celanese. Treat for about three- 
quarters of an hour in a boiling bath containing 2 grams of olive 
oil soap, 5 cubic centimeters of Turkey-red oil and 0.25 grams of 
soda ash per liter. This treatment may slightly weaken the fabric, 
but this has been stated to be only to the extent of about 2 per 
cent. 

R. Clavel, in British Patent No. 206,818, September 19, 1923, 
covers the production of wooly effects on acetate silk or fabrics 
containing it by means of dilute aqueous solutions of acetic or 
formic acid at about the boiling point. To restrain the effect 
and conserve the strength and elasticity of the acetate silk, pro- 
tective colloids, such as gelatin, soap, and Turkey-red oil, or salts, 
such as sodium chloride or sulfate, or magnesium chloride, are 
added to the bath. For example, the acetate silk may be treated 
for an hour in a boiling 8 per cent solution of acetic acid contain- 
ing 0.5 per cent of Turkey-red oil, on the weight of the solution. 
It is then washed, soaped, and treated in the usual manner. Dull 
or mat effects are produced by boiling soap solutions, barium 
salts, or phenolic substances. 

According to British Patent No. 260,312, May 26, 1925, to 
C. W. Palmer, S. M. Fulton, and the British Celanese Company, 
the luster of acetate silk in the form of threads, fabrics, or other 


440 ACETATE SILK 


materials, either alone or in the presence of other fibers, may be 
modified by treatment with hot or boiling aqueous liquors which 
may or may not contain delustering agents, and in the presence 
of suitable quantities of the protective salts, as mentioned in- 
British Patent No. 246,879. Steam may also be used to modify 
the luster. Cane sugar is a protective agent in addition to the 
neutral salts mentioned in the above patent. 

German Patent No. 411,798 covers the production of wool-like 
effects upon acetate silk by treating the yarn or fabric in a soap 
solution containing about 0.5 per cent of fatty acid and 8 per cent 
of acetic acid for one hour at the boil. The material is then 
washed well and treated with an oil emulsion to soften it. 

H. Dreyfus, J. F. Briggs, and H. R. S. Clotworthy received 
United States Patent No. 1,554,801 on September 22, 1925, upon 
a process of crinkling and delustering cellulose ester fibers, such 
as acetate silk, by means of a hot water or ammonium thiocyanate 
treatment. They state that this gives an effect similar to wool, 
hair, etc. 

In applying sizing, filling, loading, or stiffening materials to 
goods containing acetate silk, or in fact any other variety of rayon, 
where it is desired to retain the luster of the rayon, only trans- 
parent materials should be applied, as the opaque mixtures, 
such as some starch finishes, obscure the luster and brilliancy 
of the rayon very considerably. The use of starch finishes 
on materials containing acetate silk is not always as successful as 
could be desired,* owing to the fact that it is not taken up by the 
acetate silk very well, but forms merely a scale or coating on the 
surface. Where a stiffening effect is desired, some other materials 
are usually more successful and are generally applied at 50 to 
60° C. (122 to 140° F.). Gelatin, gum tragasol, white dextrin, 
kana gum, and bleached Irish moss have been suggested for this 
purpose. 

A number of more or less “physical or mechanical” effects are 
also possible on Celanese, and probably, under suitable conditions, 
to Rhodiaseta and Lustron. A so-called “Cire” finish may be given 
by passing the Celanese through calender rolls at a fairly high 
temperature,® so as to partially fuse the fiber on the surface. 


A oe 


SIZING AND FINISHING AAI 


Fabric finished in this way will not spot and is useful in the 
millinery and related trades. A metallic or candy-like luster is 
also possible on Celanese by suitable hot calendering. Generally a 
suitable luster is obtained by only one or more passages through a 
cold calender special lustering machine, without the use of either 
high temperatures or pressures, which should be avoided if pos- 
sible. Some one has suggested the mechanical printing or embos- 
sing of designs, effects, etc., on Celanese materials by means of hot 
suitably engraved rolls under the correct pressure. Obviously 
such effects are highly specialized and would require special equip- 
ment and experience, as well as very careful attention to details in 
order to avoid injury to the fiber or fabric. 


Fimshing Patents 


British Patent No. 249,946, January 10, 1925, to the British 
Celanese Company, T. C. Woodman, and W. A. Dickie, covers a 
rather unusual finishing process somewhat along the above lines 
for special purposes. This patent states that waterproof or gas- 
proof fabrics can be prepared by heating and at the same time 
pressing woven or knitted fabrics made wholly or in part of yarns 
or threads of filaments or fibers of cellulose esters or ethers or 
mixtures of these. The fabric may first be coated or sprayed 
with, or there may be incorporated with the filaments or fibers, 
plasticizing or softening agents or solvents, such as triacetin, p- 
toluenesulfonamide or its derivatives, p-toluenesulfonanilide, high 
boiling alkylated xylenesulfonamide derivatives, or diethyl phthal- 
ate. The softening agents are employed particularly for making 
gas-tight fabrics. The heat and pressure may be applied by a 
variety of methods, as described in the patent, and the extent of 
the melting effect to be produced on the filaments or fibers of the 
cellulose derivative may be varied by altering the conditions of 
temperature, pressure, or duration of pressure. 

For instance, an all acetate silk fabric may be pressed between 
smooth plates at about 100° C. (212° F.), under a pressure of 
500 pounds per square inch for 5 minutes, to give a waterproof 
fabric which retains the structure of the woven fabric. Or the 
fabric may be slowly passed through heated calender rolls at 100 


442 . ACETATE: Sis 


to 180° C., under a pressure of 300 to 600 pounds per square inch; — 
or it may be passed repeatedly between heated rollers. In order 
to increase the melting effect produced on the fibers the fabric 
may first be treated with a solution containing 20 grams of mono-_ 
methylxylenesulfonamide in 100 grams of benzene for each 100 
grams of fabric. The temperature and the pressure, or duration © 
of the pressure may be increased to cause the fibers to coalesce 
more or less completely. 7 

British Patent No. 254,354, February 6, 1925, to C. Dreyfus | 
covers the application of the process described in British Patent — 
No. 249,946 to the production of pattern effects on fabrics com- 
posed wholly or in part of the ethers or organic esters of cellulose, 
such as cellulose acetate. The fabrics are treated with heated 
engraved rollers or plates under pressure, whereby a pattern effect 
is obtained due to the melting or softening action, the degree of 
which may be varied widely up to a complete melting together of 
the yarns. 

British Patent No. 256,666 to H. H. C. Wilcock covers the 
production of figured gauze fabrics, etc. A leno or other fabric 
is woven on a one-shuttle loom with a multiple filament weft com- 
prising material which is not susceptible and material which is” 
susceptible to the action of a solvent or agent in a subsequent car- 
bonizing process, for example cotton and silk, wool, or acetate 
silk. Thus, one fine cotton thread and one acetate silk thread are 
wound on the same pirn so as to be introduced at the same pick 
but not twisted together. A colored pattern is printed on the 
fabric and the fabric treated in the unprinted portions, by means of 
an engraved roller, with a solvent or modifier (sodium hydroxide ) 
for the acetate silk. 


_ Relustering Celanese 


In cases where Celanese has lost its luster due to too high a tem- 
perature in scouring, dyeing, or other treatment, it may be re-" 
lustered in two ways, the first of which is possibly the most satis- 
factory, but the latter is much quicker. Where the Celanese is 
glazed from hot ironing, Method No. 124 may be used. 

Method No. 122: Relustering Dulled Celanese. Steep the goods 


SIZING AND FINISHING 443 


for 3 hours in a cold 20 per cent solution of acetic acid and hydro- 
extract without rinsing. Dry in a hot stove and then remove 
any remaining acid by a thorough water washing, followed by a 
light soaping. 

Method No. 123: Relustering Dulled Celanese. The above 
method may be hastened considerably by using a 25 per cent solu- 
tion of acetic acid, instead of the 20 per cent solution. In this 
case the steeping time is reduced to only one hour, instead of 3 
hours. 

Method No. 124: Refinishing Glazed Celanese. Steep the goods 
for about an hour and a half at 85° C. (185° F.) in a 20 per cent 
solution of sodium chloride. This causes the surface of the fibers 
to swell out and assume a normal appearance. 


Relustering Patents 


The relustering of Celanese is covered by British Patents No. 
209,265 and No. 259,266. The former, dated May 26, 1925, to 
the British Celanese Company, J. F. Briggs, J. T. Kidd, and C. W. 
Palmer, states that acetate silk, either alone or in admixture with 
other fibers, which has lost its natural high luster in the various 
wet processes of manufacture, may be relustered completely or to 
any desired extent by treatment with aqueous solutions of one or 
more substances which are solvents or swelling agent for cellulose 
acetate. The compounds mentioned include acetic acid, phenol, 
benzyl alcohol, triacetin, cyclohexanone, and ammonium or other 
thiocyanates. The duration of the treatment depends upon the 
concentration of the reagent, the degree of luster it is desired to 
impart, and the temperature, but the conditions must not be such 
that fusion or permanent deformation of the filaments results. 
In general the temperature should not exceed 30 or 40° C. (86 or 
104° F.), and 1 to 5 hours is a convenient time of exposure. 

After treatment the material is centrifuged and allowed to dry, 
preferably without rinsing, at a temperature not exceeding about 
40° C. Rinsing is avoided in order that the ratio of swelling agent 
to water in the liquid retained by the filaments is not materially 
reduced. For this reason it is best to use those solvents which 
have a boiling point higher than water. The following. are ex- 


444 ACETATE SILK 


amples of suitable solutions and temperatures: 15 to 20 per cent 
of acetic acid, by weight, at 20° C. (68° F.) ; a 1.5 per cent solu- 
tion of phenol at 15 to 20° C. (59 to 69° F.) ; a saturated solution 
(1 to 1.5 per cent) of benzyl alcohol at 20 to 30° C. (68 to 86° 
F.) ; a saturated triacetin solution (about 1 per cent) at 20 to 30° 
C.;a5 to 7 per cent solution of cyclohexanone at 20° C.; 200 to 
250 grams per liter solution of ammonium thiocyanate at the or- 
dinary temperature; or a 6 per cent solution of alcohol. One 
hour’s treatment is usually sufficient. 

British Patent No. 259,266, May 26, 1925, to the British Cela- 
nese Company, C. W. Palmer and S. M. Fulton, states that acetate 
silk threads which have lost their natural high luster by immersion 
in boiling aqueous liquors may be relustered to any desired degree 
by immersion in boiling, or nearly boiling, aqueous solutions of 
neutral salts( see British Patent No. 246,879) or sugars. Suitable 
salts include the sulfates and chlorides of ammonia, sodium, potas- 
sium and aluminum. For example, delustered acetate silk is re- 
lustered by immersion for 10 to 40 minutes in a boiling aqueous 
solution containing 1 to 6 per cent of sodium sulfate; or 2 to 95 
per cent of ammonium sulfate for 10 minutes; or 5 to 10 per cent 
of cane sugar for 5 to 20 minutes. Alternatively, the delustered 
silk is subjected to the action of a swelling agent, such as am- — 
monium thiocyanate (see British Patent No. 158,340), before 
treatment with the relustering solution. 


Washing and Dry Cleaning 


While washing and dry cleaning are not usually considered as 
finishing operations, they are sometimes necessary in refinishing 
soiled articles. In such cases the goods should be washed by the 
methods given in Chapter IX under Scouring, and handled in the 
same manner as true silk, rather than as cotton, the length of time 
and concentration of the bath being varied according to the neces- 
sity of the materials being washed. The matter of temperature 
and alkalinity of the wash water must be controlled in this case 
just as in all others on goods of this class. 

Where acetate silk or materials containing it are to be “dry 
cleaned,” care should be taken to select solvents which do not act — 


SIZING AND FINISHING 445 


upon either the fiber or dyes. Such solvents as gasoline, benzene, 
solvent naphtha, toluene, xylene, turpentine, or pine oil are recom- 
mended, the last two being used more in the removal of stains 
than in dry cleaning. Solvents of the chlorinated hydrocarbon 
type, such as chloroform, carbon tetrachloride, tetrachlorethane, 
trichlorethylene, etc., as well as phenol, are to be avoided or used 
with caution. 

Recent tests’ on the dry cleaning of fabrics composed of a 
cotton warp and Tubize, viscose, or Celanese weft, by dipping 
the goods in a solution of 20 per cent ammonia, soap, and naphtha, 
in a commercial drycleaning plant, and drying at 54 to 66° C. 
(130 to 150° F.), show that with proper handling the fabric is not 
injured. 


References 


1E. R. Woodward, Textile World 69, 1827 (1926). 

2A. H. Grimshaw, Textile World 67, 320-1 and 1397-9 (1925). 
$G. H. Ellis, J. Soc. Dyers and Colourists 42, 186 (1926). 

*H. Blackshaw, Dyer and Calico Printer 55, 225 (1926). 

®R. G. Dort, American Dyestuff Reporter 15, 158-66 (1926). 

® Anon, Textile World 17, 945-7 (1927). 

7 Nat. Assoc. Cotton Méfrs., Bull. No. 74 (1926). 


” 


A he es ee 


PALENT INDEX 


United States Patent Application 1,551,112 


4,551,330 
as ia sa 6 0 b's os 19 = 1,554,801 
WS7 ioc 
United States Patent Reissue No 1,574,748 
i TS ee 1 1,575,324 
1,583,475 
United States Patent No 1,586,911 
i a 20, 26 1,587,669 
eee, ike ops oe seis 2045 1,588,951 
eee see's 19 ~=-:1,595,178 
oh ee a 45 1,599,748 
ET a yk ooo sia ss 19  ~=1,600,159 
eeleeecsr, 251, 32 1,600,277 
yy as cise e «oe 8s 1,602,695 
eo ae 5) 1,607,474 
(ona a 41 1,609,702 
a ee eee 221 1,610,961 
a bi a ree eee 42 
i Sen eee 42 British Patent No 
-. oe eee ea MODS Oday ase since wn 0) oo 6 Oe ewes 
a ee e103 Van cee ne rs eee eenrnae nos 
ol ee eee ee N TAS UE ceux) esac} Camas 
oh ee eee 0 tO O70 cs cle a vara bos ee © bate mane 
Le er ee Be rh DUS ey, ea Ra Ae ee Rtas cen 
PP hs es vnc eh ds es BPD PLT 343 sonic cawes cone te ch eee 
issue as 151, 184, 204, oe P6255 ie Sy erin cegaie ope eee eee 
on 2 EGS eee 1200 5s satus to hs oe eee cere 
at 52 LBO04 Ce. aie = ae tte ohne eee 
et Ee Pee AS S30 Dirac cues CS oles eee 
us He eee eee DATS oe cic eal tt ace 6 ole Teale acraene 
a ae We ar OOGwist a. us ayers ate me reone 
_ he ee A Ameer) 520,97 54 es rca a> ae sles oe eee 
ee ods + « DEle he0976 © ecatns oo ees te ere ere 
Do BO 723, 968.0 Saha a neee aaron 
Gack as cae ss TAS 4 009% cs en tye ores tae 
6 BG era DA LBA oie wien nha eae slope eer 
1 ee 1R6 2 324382. as 5 sce sin eae Peg te eres 
RN a wes Baal. 925,G4L 5 iat nies ao ate ote 
a Raa e Paes 25d | 102,310) aan. ee etre ce een Geta 
Jo Oo ae 332° [03 O38 cites nth es lseee .eeetes 
eee S1iR~ (125, 1536 A eee en 
ee a ka ss 187-180) 130 232% wa Gowie vee ome ee 
od ee 193 150,9 on aah eae alata eamee 
ee 211 158340. 
i he in vs 5s Di?: 165,519. <5 ees ene ae ee 
ee 226 169,741 I ches Matis oa yn ean x 
ME ge bas « 1473222 VTE ASHE aha va aah ee 
447 


oeeeere ere eee eee eee eee ee 


eoocecerreer eee eee eee wwe eee 


eooveererer eee eee ee ee ee ow 


eoorererer eee ee ee ee ee ee ee 


eoovreeree eee eee esos 


eceveeereree eee eee eee ew wo 


eceoreeveeree eee ee ee ee 


eoseeverecrerev ee eer eee eee ee eo 


eorceveeveevrerer ee eer ee eee ee @ 


evreveeeveree eevee ee eee eee 


eoseerreoer eee see eee eee eoeve 


oeseerereererer eee eee ee ee eo 


eecerevoeerwer eer eee ee ee ee ew 8 * 


eevee ecerer ee oe eee eee ee oo 


oeceo3nrre eer eee ee ee eee ee ee 


ercecereoeerereoee ee eee ee ee oo 


448 ACETAL Siig 


BAO 034 sii suc t anya wre seem ay tee 260 2245359 oe eee ee 224, 318 
1/0; S395. serie cov eee e eres 147, 222 224,303 2.05 se eee 187 
178,946 28 Na ees ce ee 262° :224,081 aun 319, 325, dam 
LTO SBA a aa 160, 161, 204, 206 224 9255s 311, 319, 327, 323) 
131,750 ii cis oaietiee eaee 198 225,676 “cs 2. ss eee 3, eae 
12,031 Sse ua wach nies he etn ves 201 225,862). oon 188, 189, 194 
TB2,B30 Seite aerate 116, 147, 222, 281 226,309 J5. 2s oe ee 42 
LBZ SAA oo het a dencior antes aos enn 148 =©226,948 _ 2c eee 116, 168, 188 
TRS BOG 2 ioe rset ielona tn alcistal ale ema 259 227,140 scene a ee ee 42 
LEDS ZS S69 sini iced apn alte tak pane Aen 199 227, 183. oo ee 320, 325, 32m 
LE) BOR oe G5 5 cal ve a 147, 221, 222, 225 227,923) Coe ee 313, 320 
WOO SLI stan chepiccater sonar ateraba a eaters 184 228,557 s.0cdwadecns eae 189 
11 TZ0 haa pine cect yates xt eae 377 © 228,634 |. ein see ee 326 
BERL 59.3 oui votate topo rales le ataeees 204, 212 230,055 22/2256 eet ae eee 189 
VAS Be DR PERE ee et ames rH OTe 259 2Z30j)D16. ..).cceeee 315, ‘S28 
LGB GAD: ban tic. oadaos cies i, ene 222 -230j;130.. 2s ogi ete ee 326 
1B OU ctkct Berd nokotetet oko es Me 260 200,457 12.70 e ane 5 ae 193 
DOF AA Rove ster cs Meriveit iver one oe ame 200-231 20Gscc eee 315, 321, 326, Sas 
TOG SAS tec washlereveketenet ciheeehgax sea gere 226 8231455 vistenann eaten 224 
2515, 920) >i. papacy cashar es vhacetp ies re 260 231806 ....4,..s0eewe eee 47 
107 BOO dialed tontontaletarcionta ee 274 = - 21,897 nie np wae aay ee ee 162 
LOO AOA cu nie aa eb 147, 216,:222 . 232,599) ian 190 
POR ld hae aeay dp hood ok ee » 275. BBS, 704 die ewe career 335 
PL OR ale Werainin ey aang 312, 313, 320 | 233,815 027 21, ae 
OZ EDT tata ee vena ed oie 85, 224. “234,533 "ess ek ee 322 
BOS OS iiaie oe os cassie pe a Ree ee 314 236,037 > vcnnoes deena eee 323 
NAS BN gee Car ah 147, 222, 223 237,507. 2a ee 31 
ZORIZ0 to We heawavemetae hae 86, 306 237,739 cuasen noes geen 197 
4 6 Se op er ee 63,. 135, 349, 350 237,909 Saya ee ee 345 
BUGS US Fauienstciciatenncansteceer ease sent erae 39 «:237,943) aoe 323, 324, 32a; oe 
Sd ine wp Aa 195, 312, 313, 320 238,590 (05 hee 335 
ZLID SADE Poe oahesavtanerghetonaaetoraany tar ee Gites 61 238,717 Tid. tease eee eee 276 
Gt Gi2OD ein, acs, sraraurelalvse alana aoe 436 238,721. ooo vse eee 362 
De AGA Us, pesto ertthanskeri beta ashore tata 56 238,842. odin. eee 40 
ble 20 ha nes AAG weet 268, 314, 318 238,930.02 ee 324, 326 
PLL BOG ich, Ser rcioenialeim ca feondevaerenceee ae Al 239,470 ip ccotecetn acorate ae Rae 324 
PBF 28 ERR eno Re re ARE 275 240,208 0. ocean eee 164 
PA WA LS CUSBrEtaaE oO mee by mere omer e 2 275 2A0,514 | nn oes acto nate 149 
FA AS K Boe ue ueity 2 ee men er 161 = 240,624 © i nsce ernie cee ae 35 
AA AUZ Rita teen tae oes 210, 224, 364 241,854. caus on eetenrere ee i 
214240 Mirae ties g huesiae sae 314 242,393) Quen eee 311, 325) 334 
DLA) aiethcmeMASi tesa tom ntan acakaee 361. 242,719 220s ee ee 311, 325, 338 
2 Ap LOW lida g ak tab wemiene ace se 314, 321, 331. 243,505 ee 326 
AUS OU “iad atte aes o 164, 165, 262 243,737) oo ce eee 190 
PAUSE Ee Eg ets eye eee <i 148 4 «—- 243,738... «cased retain 190 
4 Dg AOD Uae adem PMA Re labe locas ee 148 243,841. oe ee 153. 286. 310 
2 5 BO0~ States ops avaterestrn ste 344 244,143 ...... 150, 152, 253, S27 eeoe 
216,838 su een ae ates cans 144, 148 244,207" bee 90 
219,349 ....211, 212, 311, 315, 319, 244,936 Vie 327 

320, VAS 324, 325, 327 244 OAT © oes. o:w siontv guard eee 435 
220; SUS Vp denn ed Nota chad hue Bs Jey 187 =. 245.758. 23 canon ole 191 
220, S05 ees ee aaa amin Ae aire hs 211, 212 245,790 191, 224 
DO2, UOT ca ode eles pete s 317, 323, 324 246,609 Jouuw.staeee eee 335 
Vie Bates ea var NY Ae oemene tne gt 338 246,879 a... «<2 sin sreraternra ie 
LAO EL eked cick ieee atctig erate 191, 318, 328 63, 135, 136, 229, 349, 386, 440 


G4 O18 hie eed mane 165, 262 246,984 oie cncee ene eeen 328 


Peel ENT INDEX 


BG tae ne wee honed 4 ass 318 
MR SMP elec vnie win'y os 8 6 oe 151 
0 OMIOD heals ae 435 
Mey nals wis cae es oss 40 
Occ ac tare cnsces-- 191 
ee alien cine 5 f,0++-. 47 
2 oe a 193 
oy RE ee 441, 442 
EG A a 328 
es kaos cuits ess 192 
Oe 193 
OV AUR 28 Ae 276 
ENO 6 ee 193 
aS 5a Hore Ves 
ed a ney so ee es ee 47 
ses isc ee ayes +o 46 
ON eens fialsip se oe ss 328 
GSS a ye a a 442 
ESE A Se a HR RAN 
Eh BS) Se 329 
RE ers OE. Gases a's es oe 340 
Aas Sep cee pss 329 
NOLS 0 nieces * er. ar 442 
US a Ee 329 
| ok nate el 194 
LN 5 Er ZY 
Re i iva pices sss ae) 
ee ee te 5 cee ee. 330 
AO soe 443 
Gc Ls i a 443, 444 
UC EYS andy eee rr 439 
ee aah ore a5 k's es ces 343 
OSS a a S40, °422 


SON og 19 
Ree A Ee Re PG. ES cs ta oes 19 
ERE» A] a 42 
German Patent No. 

SRS es a 251 
SOIR NOME Sor, coors toes ce eo 108 
8S es a 220. 252 
RI oo xcle sic vs os 149, 253 
ee a ee ee eee lee 41 
eee eG See we ee 40 
te ee, alse a ws 40 
AN 1952627, 33, 67 
EA OS See eae ee 319, 330, 334 
ee file a sls vss oss 335 
NN Re GI se 8 + 116, 148 
ae ee a 135 


449 
nl 1 / OS: eon Suna neteae ee ae eee 440 
ALS AW) Renae eam Te ar nin ta ale 194 
EO Sines ct ee ene en arate ee 194 
ef SONAL nappa ian con ener ie 188, 194 
ALON Oger apes te ee cea e ok 225 
Pe MN ET oe ie Mer Set eee ie 422 
French Patent Application No. 
Acad Pe Ee a ay py Seely o Paras Ace Ne 224 
French Patent No. 
O24 GOOLE ten aT ahe o or omhe ache ele eta aes 26 
Spr eR WTAE foie ner ie Re KAR, Phresh eal is 19 
ios fae Lint Ricee oehisva ote he ae Mere alee Zoe 
ALAS / mies fear ca eomn let One 19 
OG 5 OOO Te re yo ee ee ee 220), mee 
ALZAVIEM bie cise ore cua eee ee AO 
“Bi CRY LGV Cen rs prank ori 259 
AZT AAS CRO Sed eek tet nC tee oases 41 
Ae DOAN ek sate ale aie Sea ep 19 
A PEA OR ie ee cer tne iaateetet eae an 42 
VIDA OSE Baty depen Mae mre te WM ne Fo 28 
Bs OC Aree aver pe secre ome neve ee 261 
BOS: DOU ae Ae ee ee ee 163 
S/AALG AS oe ie beeen te ites eee 161 
tae fi Rad a Pe fea rg Seba UR AGN Se kh <A 157 
OEY 7 Senin oe teas ae ee ontbeee are co eet 261 
GOUMDG rates. hae te totee sinner nae 328 


Austrian Patent Application No. 


ego Onda eee oo ay ceine en vet ee 41 
Austrian Patent No. 

AVAGTT tke take sree ek «eee eee 19 
Belgian Patent No. 

TS SUG oo aur tae lee eis ae eee 19 
53. 1 OU) © oatdavcass's apens siete see tee ate 41 
ZAG OLA Sie ee saa oc ct essstee seen ee eee 42 
Canadian Patent No. 

0) RAS Bee Stree oie eee 19 
CORIO! CWP ute Rn AS Ai 5 oe 19 
DOO 3 Oe oa eso od oe eee 350 
POU SSO ee ede shee eee 319 
Hungarian Patent No. 

35 COG oe.c& oes sum ns yetahe Sone ete terme 19 
Swiss Patent No. 

LOO, 7ORe | Pet Seis ee ree 259 


NAME 


Abel C.D, 2513265 

Actien-Gesellschaft fur Anilin-Fab- 
rikation, 177, 215, 244, 251, 265, 
400 

Aische, M. I., 171, 183 

Alexander, G. J., 22 

Alpers, G. H., 6 

American Aniline Products Com- 
pany, 284 

American Cellulose and Chemical 
Company, 6) 21,430, 211,257) ean 
346, 374, 391, 395 to 400, 412 to 
414 

Anderson, E. B., 185 

Archer, B. K.:7 

Aschkenasi, S., 330 

Associated Knit Underwear Manu- 
facturers of America, 6 

Audemars, 17 

Awcock, G. A., 435 


Baddiley, J., 185, 187, 195; 211,312, 
313,314, 318, 320, 322, eyeP 328 

Bader, W., 260 

Badische Company, 113, 5149-3165 
1560804 215,223, 261, 306, 328, 
341, 391, 397 to 401, 413, 414, 415 

Barnard, Gi Mero? 103 a0 

Barnett, W. ie 30, 34, 42 

Bate, S. C.,.197 , 

Bayer & Company, Ba 19220,5 20; 
7 41, 144, 148, 180, 188, 193, 194, 
203, 248, 314, 397 to 400, 415 

Beckett, E. G., 321, 324, 328 

Beltzer, | Sage! & ee 80 

Bensancon, 147, 155 

Bertolet, E. C.. 6 

Bevan, E. os 

Blackshaw, eh 164, 318, 354, 357, 
437, 445 

Bogan, 1H Ee 

Bonhote, G., 187 

Borzykowski, B., 42 

Bouvier, M. E., 261 

Briges, J. Fa 351, 155, 183, 206; 212; 
225, 230, 257, 262, 440, 443 

British Alizarine Company, 192, 
193, 330 

British Celanese, Ltd., 21, 107, 142, 
215,°227,. 249, “260, 283, SLO ols, 


? 


450 


INDEX 


319, 323, 324, 325, 327, 328, 395 .ee 
400, 412, 413, 414, 435, 439, 441, 


443, 444 

British Cellulose and Chemical 
Manufacturing Company, 39, 151, 
257, 260, 262, 315, 319,.320 

British Dyestuffs Corporation, 89, 
197, 164, 177, 185, 187,, 188, 19m 

194, 197, 198, 212, 215, 274, 

ae, 277, 298, 299, 300, sim 

: 314, 318, 320, 322, 323, 328, 

, 343, 346, 362, 374, 395 to 400, 
413, 414 

Brotherton & Company, Ltd., 171 

Browning, Jr., H., 211, 322 

Bucherer, 277 

Bulow, Wo 110, 112s 

Bunker, H 1 70 

Burgess, Ledward & Company, 160, 
184, 222 


ae A., 32, 36, 42, 62, 70, 111) 1a 
12 


Calico Printers’ Association, 344 
Canadian Celanese, Ltd., 21 
Carpmael, W., 148, 193 

Cartier, 259 

Cassella & Company, L., 113, 215, 
241, 397 to 403, 413, 414, 415 

Casten, P., 298, 311 

Celluloid Company, 42 

Chardonnet, H. de, 18, 64 

Chase, W. W., 354, 357 

Cheney, R. AS 

Ciba Company, 7, 102, 187, 205, 20G; 
224, 307, Stas 329, 395 to 401, 412 
to 414, Al? 

Clavel; R., 114, 115, 116, 147,75 1a 
171, 204-222 eee 222. 223, 2am 
226, 265, 281, 331, 439 

Clayton Aniline Company, 361 

Clayton, E., 74, 75, 82, 84, 89 

Clotworthy, H. R. S., 440 

Coffin, Jr., C.bi 73? 

vest des Textiles Artificiels, 

Cotton, W., 338, 346 

Croft, (Ge Wieto.s 

Cross, C.F, 16.0208 


ee ee ae 


NAME INDEX 


eavics ft. R., 6, 13, 164, 165, 342, 
343, 346 

Deschiens, M., 25, 27, 42 

Dickie, W. A., 441 

Debroyd, J., 89 

Mortis. 0, 77, 59, 138, 155, 214, 
230, 286, 288, 297, 374, 386, 391, 
417, 422, 438, 445 

Drescher .H, A, E., 314, 331 

Dreyfus, C., 18, 19, 20, 259, 346, 442 

Dreyfus, H., 18, 19, 20, 28, 440 


Duisberg, W., 194, 195, 277 


DuPont de Nemours and Company, 
Ee ds 7, 338, 362, 395 to 401, 412 
to 415 

Dyestuffs Corporation of America, 
6, 299, 395 to 400, 413, 414 


Edwards, W. F., 70 

Eichengruen, A., 36 

Eichwede, H., 196 

Ellis, G. B., 40 

Pili Gor. 108, 211, 227, 281, 297, 
uo Pols, 319, 320, 324, 325, 
327, 328, 339, 340, 346, 374, 445 

Emmons, G., 174, 183 

Entat, M., 36, 42 

Esselen, Jr., G. V., 42 

Evans, J. M., 362 


Feibelman, R., 133, 136 

Fischer, E., 196 

Foltzer, J., 42, 103 

Formhals, R., 78, 89 

Franchimont, A., 18, 22 

Prank: G f1.; 116) 188, 275 

Friedman, E., 41 

Fulton, S. M., 439, 444 

Furst Guido Donnersmarch’sche 
Kunstseiden-u. Acetatwerke, 20, 


253 
Pyie A W., 2/6 


Garner, W., 70, 86, 89 

Geigy Company, J. R., 7, 161, 162, 
ea 203, 338, 339, 359, 397 to 409, 
1 

General Dyestuffs Corporation, 6, 7 

Gillard, 259 

Ginsberg, I., 77, 89, 112, 125 

Goldthorpe, W. O., 325 

Gotze, K., 56, 70, 79, 89 

Grandmonyeu, 20 

Grasselli Dyestuffs 
189, 196 


Corporation, 


451 


Green, A. G., 108, 124, 125, 197, 198, 
264, 274, 275, 277, 422 

Greenhaloty iy GZe 70811011 124) 
1251 34 bbe 21S 2508 2a0) col. 
297, 327, 426; 430,°431 ; 

Griesheim-Elektron Company, 215, 
218, 219.220) 247 

Grimshaw, A. H., 48, 70, 126, 127, 
129, 136, 432, 445 

Gunther, F., 186, 194 


Haerry, |; -A,-93, 09, 150,155 

Bagers Hoek 7. 

ball, AV]. 1007410221035 00m Ios 
Poe IL Loe aacee. ols ote 

occa Ry 8489297, L1G tesa! 

Hamline @. ries0 

Hamm, H. A., 81, 89 

Hanney, 152 

Harrison, W., 80, 89, 160, 184, 222 

Piasearn 49 7.65.270 

Heberlein and Company, 345 

Henckle von Donnersmarck Artifi- 
a Silk and Acetate Works, 20, 
Z 

Henderson, J. A. R., 194 

Hentrich, W., 194, 195, 277 

Herzog, A., 64, 66, 70, 85, 89 

Herzog, R. O., 38, 42, 67, 70 

Hess is, 38,42.56/.°70 

Heuser, E., 24, 34, 42 

Hill oJ n185, 194318) 323,328 

Holliday & Company, L. B., 218, 
230, 327, 397 to 400, 402, 416 

Hollins, C., 190, 191, 329 

Hooke, R., 17 

Hooley,.14 3. 4.022 

Hopttatts 225 

Horsfall, R. S., 194 

Hubner, J., 91, 97 

Hugel, G. L., 157 

Hummel, 49 

Humphries, R., 90 

Hunter, A. E., 377 


I. G. Farbenindustrie A.-G., 191, 
196, 225, 333, 422 

Imison, M., 100, 103 

Imray, O. Y. (see Ciba Company), 
314 


Jackman, D. N., 48, 70 
Jancke, W., 66, 70 


452 


Johnson, A. K., 49, 58, 70, 72, 76, 
89 


Johnson, J. Y. (see Badische Com- 
pany), 149, 328 


Kalle & Company, 307 

Karrer, P., :/0 

Kartaschoff, V., 114, 125 

Kay, H., 419, 422 

Kidd, J. T., 443 

Kilby, W., 210 

Killheffer, E. H., 7, 411 

Kinkead, R. W., 93, 94, 97 

Knaggs, A. B., 93, 07 

Knecht, E., 93, 97,2151 

Knoevenagel, Re 108, 125, fz lypstpes 
253 

Knoll and Company, 220, 252 

Knowland, D. P., 7 

Kraise, P., 80, 89 

Kruger, D., 38, 42 

Kuhlmann, 147 


La Celanes Francaise, 21 

Lahousse, J. E. G., 40 

Lang,oK.,.09 

Lange, F., 194 

Langmuir, 1. 5t?, ies 

Lawrie, L. (a 164, 194, 210; 212, 
318, 328 

Lederer, L., 40 

Leitch & Company, J. W., 219 

Levy; Li) A.,. 35, 42 

Liberty By-Products Company, 7, 


Lilienfeld, L., 46 

Lindsey, W. G., 42 

Little, = D2 eo 45 

Little, 58, 70 

Lodge, E. 362 

Luft, M. GS 46, 54, 60, 65, 70 

Lustron Company, 6, 20, 39, 62, 136, 
163, 165, 206, 257, 259, 355, 358 


Mahnken, C. W., 7 

Mallabar, H. J., 29 

Marshall, W., 56 

Maschner, P., 81, 83, 89 

Massot, W., - 

Matos, L. 7 

Matthews, J. L. 82, 89, 103 

Meister, Lucius, and Bruning, 189, 
190, 215, 227, 239, 397 to 401, 415 

Mellersh- Jackson, W. J., 41 

Mendoza, M., 276 

Mennel, i 06, 97 


ACETATE SILK 


Mertin, H. W., 7 
Messmer, Ee 67, 70 
Metzger, R., 149, 196, 333 


Mo K. H,, 110, 112, ‘113,42 

22 

Miles, G. W., 18, 19, 25, 26, 27, 106, 
253, 204 

Milne, W., 136, 346 

Minajeff, 97 


Mitchell, W. E., 7 

Moffatt, M. R., 7 

Moncada, C., 70 

Monnet, P., 259 

Montmollin, G. de, 187 

Mork, H. S., 5, 20, 26, 39, 45, 62, 
106, 256, 257, 258, 259 
Morton Sundour Fabrics, 210 
Moser, W., 314 

Mudford, a D362 

Muller, C. E., 189 


Muller, F., 151 

Mullin, C. Ase 212, 263, 297, 374 
Munz, F., 332 

National Aniline and Chemical 


Company, 395 to 400 
National Association of Hosiery 
and Knit Underwear Manufac- 
turers of America, 6 
Newport Chemical Works, 7, 103, 
284, 308, 309, 367, 393 to 397, 411 
Noil Chemical and Color Works, 7, 

258, 398 to 400 


Obermiller, J., 70 
Olney, L. A., 6, 9 
Oppe, A., 56, 70 

Ost, H., 30, 32,°3o.ma 
Ott, E., 66, 70 


Palmer, C. W., 47, 70, 151, 439, 443, 
444 


Paneth, F., 112, 125 

Parker, R. G., 48, 70 

Patchett, R. V., 136 

Peerless Color Company, 401 

Perkin, W. H., 190, 191, 197, 276, 
329 

Petzold, K., 89 

Pokorny, ie 144, 155, 2138, 216, 2a 
227, 20 338, 346 

Powell, 18 


Rabe, P., 148 
Radu, A., 112, 125 
Ransford, 148 


Pe ae gee ee ee a 


NAME INDEX 453 


Raecer. B.C. 90 

Reaumur, 17 

Remlin, F. {ES BPs 

Rhodes, OF e 79, 80, 81, 89 

Richardson, i 1h 260, 262 

Ristenpart, C., 89 

Roberts, F., 344 

Roetel, B., 165, 263 

Rose, R. E., 7 

Rowe, F. M., 125,238,230, 277 

Roy, pet B..739 

Rudolph, icy 422 

Ruperti, A., 84, 89, 116, 125, 256, 
263 

Ryley, C. F., 435 


Saget, 65, 70 

Sanderson, Wis. 155; 183,. 230 

Sandoz Chemical "Works, 191, S Sey 
395, 396 

Saunders, Kee etus, 124, 125, 197, 
198, 264, 274, 275, oT}. 422 

Schaposchinkoff, 07 

Schenke, E. M., 6 

Schneevoigt, A., 70, 337, 342, 346 

Schreiber, W. 4s 81, 80 

Schuetzenberger, "P., 18, 22 

Schultze, G., 67, 70 

Schuster, C., 110, P13. t25 

Schwabe, @, 17 

Schwalbe, (ala, (9, OD, 09 

Scottish Dyes, Ltd., 7, 106, 298, 300, 
308, 314, 321, 322, "324, 326, 328, 
329, 334, oan 364 

Shepherdson, A 314, 318, 328 

Silberman, 64, 70 

Silver Springs Bleaching and Dye- 
ing Company, 229, 317, 349 

Smith, L., 343 

Societe ‘Alsacienne de 
Chimiques, 164, 165, 262 

Societe Anonyme des Etabissements 
Petitdidier, St. Denis, 340 

Societe Anonyme des Matiers Col- 
orantes et Produits Chimiques, 
St. Denis, 215, 236 

Societe Chimique des Usines du 
Rhone, 20, 21, 31, 135, 259 

Societe pour fa Fabrication de la 
Soie “Rhodiaseta,” 6, 20, 21, 40, 
135, 259 


Produits 


Society of Chemical Industry of 
Basle, see Ciba Company 

Springer, J. F., 89 

Sproxton, F., 42 

Stevenson, F. M., 319, 352, 374 

Stokes, W. H., 70 

Stotijck., 4 ol) 

Suchanck, W., 47, 70 

Suevern, 65, 70 

Summers, FF. P.,. 7 


Swan, H., 18, 318, 328 

Swinburne, 18 

Tatum, Wy?! W., 187, 195, 342, 313, 
320 


Thaysen, C., 64, 70 

Thomas, J, 314, O21, Jeep ue toeU, 
328, 329, 331, 334, 335 

Thomas, R. F., 329 

Thomson, R. F., 335 

Teinurerie de la Rize, 261 

Todd, W. M., 391 

(orikin, =), o2l, O20 

Trotman, E. R., 75, 89 

Trotman, S. R., 75, 89 

Tubize Artificial Silk Company, 41 


Underwood, Jr., H. W., 153, 155 
Vulquin, E., 36, 42 


Walker, W. H., 20, 26, 45 

Weiler-ter Meer, Chemische Fab- 
riken vorm., 146 

Weinand, C., 195 

Weston, 18 

Whittaker, C. M.. 103 

Wilcock, H. H. C., 442 

Wilson, 152 

Wilson, J. S., 334 

Wilson, L. P., 100, 103 

Woodhead, A. E1335 

Woodman, T. C., 440 

Woodward, E. R., 445 

Worden, E. C., 18, 105 A ee) 
42, 65, 70, 85, 89 

Wyne, 18 


Young, A., 327 


Zdanowich, J. O., 29, 31 
Zeh, L., 194, 195, 277 
Zillessen, iA. F., 7258 


SUBJECT INDEX 


Acedronole dyes, application meth- 
OdS)232;1 200 
composition, 215, 247 
on acetate silk, 231 to 236 
Acetamide test for identification of 
acetate silk, 75 
Acetane, 146, 148, 150 
Acetanol, 340 
Acetate (brand) color formulas, 178 
(brand) dyes on acetate silk, 177, 
178, 359 
test for identification, 75 
“Acetate White” dyestuffs, 351, 392 
to 403, 411 to 415 
Acetates in dyeing, 139, 143, 150 
eee acid, glacial, solubility in, 


in dry cleaning, 38 

in dyeing, 139, 143, 252, 291, 301, 
354, 355, 356, 357, 359, 405, 409, 
418, 421 

in finishing, 438, 439, 440 

in printing, 338 

in relustering, 62, 443 

in stripping, 423 

mean in printing (see Triacetin), 
9 


in the dye bath (see Triacetin), 
139: 253 
Acetone as solvent, 19, 24, 26, 28, 
29, 33, 36, 37, 38, 39, 40, 41, 42, 
Gi, 74, 72. 20/040 
oil as solvent, 38 
soluble cellulose acetates, see 
Secondary cellulose acetates 
Acetonol N, 147 
Acetylation of cellulose, 23, 24, 27, 
31, 32, 34 
temperature, 23, 28, 29, 30, 31, 32, 
33 


time, 30 
Acetylene tetrachloride as solvent, 
38, 41 
Acetyline color formulas, 238, 239 
dyes, application methods, 236, 237 
dyes, composition, 215 
dyes on acetate silk, 236 to 239 
Acid dyes, application methods, 
142, 143, 170, 416, 417 
by the dispersol method, 284 


454 


mordanting action of the, 147 

on acetate silk (also see Mor- 
dant dyes), 110, 115, 121,9058 
152, 156, 160, 166 to 202, 266, 
299, 313, 351, 358 to 360, 429 


Acid groups in dyestuffs (see Car- 
boxyl groups and Sulfonic acid 
groups), 110, 114, 116, 119 

recovery, 3l 

Acids on acetate silk, 56, 58, 106, 
347, 428, 438 

sep groups in dyestuffs, 

Acknowledgments, 5, 6 

Acridine dyes, 141, 157 

After-treatment of Lustron, 


Ri 
438 
bt chrome, 120, 154, 175, 177, 


with copper, 153 d 
bite formaldehyde - hydrosulfite, 
with Katanol, 144, 153 
with phenols, 153 
with soap, see Soaping 
weirs bicarbonate, 357, 418, 
with stannous chloride, 223 
with tannin, 144, 153 
Aktivin bleaching, 134, 135 
Albumin in dyeing, 147, 221 
Alcohol as dispersing agent, 318 
as precipitant, 41 
ee: 26, 28, 30, 32, 42, 43, 


as swelling agent, 43, 77, 106, 118, 
251, 252, 444 , 
in dyeing, 43, 77, 106, 118, 139, 
213, 216, 25.2820 enee 

in printing, 339 

in relustering, 444 

in the application of developed 
colors, 213, 216, 280 

in the application of the direct 
cotton dyestuffs, 118 

in the saponification of acetate 
silk, 259 

Alcoholic groups in dyestuffs, 264 


as Se 


’ 


SUBJECT INDEX 


Aldehyde bisulfites in 
manufacture, 265 
Aldehydes in the saponification of 

acetate silk, 261 
Algol dyes, 205, 206, 320, 369 
Aliphatic bases in the dye bath, 148 
Alizarine dyes, see Mordant dyes 
Alkali Blue, 181, 415 
Alkalies on acetate silk (also see 
Saponification), 56, 57, 58, 61, 
Joe 126, 205,°254, 347, 364, 365, 
428, 438 
Alkaline copper reagent, 78 
Alkylamino groups in dyestuffs, see 
Acid and Mordant dyestuffs 
Alliance dyes, 171, 358 
Alpaca finish on acetate silk, 439 
Alphanol dyes, 414, 415 
Alum as a protective agent, 350 
Aluminates in the saponification of 
acetate silk, 260, 261, 262 
Aluminum salts (catalyst), 36 
as protective agents, 350 
in relustering, 444 
in the saponification of acetate 
silk, 260 
on acetate silk, 120, 163, 167, 226, 
228, 229 
on viscose, 46 
Amidex in sizing, 434, 435 
Amines, identification of the, 218 
Aminoazo dyestuffs, see Acid, Di- 
rect Cotton, Mordant, Devel- 
oped, Ionamine and Dispersol 
type of dyestuffs 
Amino group in dyestuffs, 107, 108, 
Hoes 114, 116/121, 122, 123, 
124, 168, 169, 185, 188, 
189, 190, 191, 197, 198, 
210.213.2351, , 265, 306, 
B10. 1315, ‘320, B20, Odds 
Dro, o/7/, 424 
Aminopyridine as assistant, 148 
ea copper oxide reagent, 


dyestuff 


nickel oxide reagent, 78 
silver nitrate reagent, 79, 80, 81 
Ammonium salts as_ protective 
agents, 349, 350, 362, 373, 408 
in dyeing, 139, 143, 147, 148, 151, 
160, 170, 206 
in relustering, 443, 444 
Ammonium thiocyanate in dyeing, 
Si isc, 154 
Amy] acetate as solvent, 28, 72, 79 
alcohol as solvent, 28 


455 


Aniline as mounting medium, 85 
as precipitant in dyeing, 160 
as solvent, 30, 38 
as swelling agent, 251 
black on acetate silk, 216, 225, 
227 
hydrochloride in dyeing, 171, 225 
in acetate silk (pinking), 134 
im dyeing, 109, 215, 221 227, 251 
in manufacture, 33 
in printing, 339 
nitrate in dyeing, 148, 149 
Anthracene dyes, 415 
Anthraquinone compounds as dye- 
stuff precipitants, 161, 162 
dyestuffs, see Mordant, Acid, 
Vat, Ionamine, and dispersol 
type dyestuffs 
Anthrene dyes, 205, 309, 367, 368 
Antichlor treatment, 127, 132, 134 
Antimony salts (catalyst), 36 
Application, machines, 288, 426, 427 
Aromatic carboxylates in mordant- 
ing, 164 
carboxylic acids as dyestuff pre- 
cipitants, 161, 162 
hydrocarboxylates in mordanting, 


- sulfonic acid as catalyst, 26 
sulfonic acids as dyestuff pre- 
cipitants, 161, 162 
Arsinic acid groups in dyestuffs, 
Ie elre 
Artificial wool, see Viscose silk 
Art Silk Colors CW, 179, 359, 397 
to 400, 417 
Arylamino dyes, see Acid and Mor- 
dant dyes 
“Assistants” in dyeing acetate silk, 
1143) 120. 144 .to Al Sie 56 1G 
251 
in dyeing acetate silk, application 
methods, 144, 146 
Autochrome dyes, 174, 175 
Azine dyes on acetate silk, 212, 315 
Azo groups in dyestuffs, 113, 116, 
121, 124, 166 to 202, 281, 298, 328 
Azoic colors, see Developed colors 
oes dyestuffs on «acetate silk, 
1 
Azole color formulas, 246 
Azole Bee application methods, 
24 


composition, 215 
on acetate silk, 244 to 246 


456 


Azonile color formulas, 241 
dyes, application methods, 240, 370 
dyes, composition, 215 
dyes on acetate silk, 239 to 241, 
375, 376 
Azonine color formulas, 243 
Direct color formulas, 305 
Direct dyes, application methods, 
304, 305, 391, 408, 409 
Direct dyes, composition, 113, 282, 
304, 306 
Direct dyes on acetate silk, 304 
to 306, 408 
dyes, application methods, 242, 
243, 244 
dyes, composition, 215 
dyes on acetate silk, 241 to 244 


Bacterial resistance of acetate silk, 
43, 64 
Barium salts as protective agents, 350 
in dyeing, 120, 147, 160, 204, 212, 
221, 22/7, 343 
in finishing, 439 
in the saponification of acetate 
silk, 261 
Bases on acetate silk (also see De- 
veloped colors), 107, 109, 118, 
119, 122, 160, 213 to 250, 264, 
265, 278, 279, 280, 281, 289, 315, 
S340 1G00y O40 
Basic color discharges, 338 
colors, stripping, 423 to 425 
dye lakes in printing, 338 
Basic dyes, application methods, 
142, 143, 170, 283, 314, 354, 355, 
S50 soa? 
on acetate silk, 107, 111, 112, 113, 
114° 118119, 134,132 to 155, 156, 
160, 165, 168, 170, 177, 245, 251, 
on 281, 289, 350, 358, 423, 429, 
43 
on acetate silk unions, 353 to 357 
on cuprammonium silk, 98, 101 
on nitro silk, 98, 99 
on viscose silk, 98, 100 
Basic sulfato dyes, 200 
Bayko yarn, 120 
Beam dyeing, 288, 366, 426 
Benzene as solvent, 28, 30, 37, 110 
compounds as dyestuff precipi- 
tants, 161, 162 
dyeing, 108, 109, 110 
in dry cleaning, 38, 445 
in finishing, 442 


ACETATE SILK 


in sizing, 436 
as solvent, 28, 37 
Benzoates in mordanting, 164 
Benzo Azurine test for merceriza- 
tion, 97 
dyes, 181, 286, 397 to 399 
Benzoic acid as dyestuff precipi- 
tant, 161 
Benzopurpurin test for merceriza- 
tion, 93 
Benzopurpurin-titanous chloride 
test for mercerization, 93 
Benzyl alcohol as solvent, 38 
in relustering, 443, 444 
Besancon silk, see Nitro silk 
Bibliography on rayon identifica- 
tion, 89, 90 
Bisulfite dyestuff compounds, 186 
Bleaching acetate silk, 126, 127, 131, 
132, 133, 134, 364, 423 
Blinding (see Luster and Deluster), 
43.56, 61, 62, 63) 73; Liz, Bee 
126, 127, 227, 437, 439 
Bluing acetate silk, dyes used, 134 
Bobbin dyeing, 288 
Boiling-off true silk, 64, 126, 134, 
135, 349 
Borates in dyeing, 149 
in the saponification of acetate 
silk, 259, 260, 262 
Brilliant Indigo dyes on acetate 
silk, 205 
British gum as a resist, 345 
in printing, 337, 339, 340, 341 
Brittleness in working, 62, 432, 437 
Brucine sulfate reagent, 78 
Burl dyes, 401 
Burning test for identification, 73, 


Calcium chloride as precipitant, 41 
resinate in sizing, 436 
on salts as protective agents, 
in acetate silk, 36, 111 
in blinding, 62 
in dyeing, 148, 204, 212, 221, 227 
in the saponification of acetate 
silk, 260, 261 
Calcium thiocyanate 
silk, 343, 345 
Caledon vat dyestuffs, 209, 286, 365 
to 369 
Calendering, 440, 441 
Camphor in acetate silk, 42 


on acetate 


ae le ae eae 


SUBJECT INDEX 


Carbamate group in dyestuffs, 192 
Carbonates in the saponification of 
acetate silk, 259, 261, 262 
Carbon disulfide in viscose, 81, 100 
Carbon tetrachloride as solvent, 28 
in dry cleaning, 445 

Carbonizing in finishing, 442 
Carboxyl groups in dyestuffs, 110, 
i2i2l 467; 168, 172, 179, 185, 
188, 193, 264, 312, 320 
Casein in dyeing, 160, 363, 373 
in saponification, 258 
Catalysts, 18, 25, 29, 31, 32, 33, 34, 
35,°36 
Celanese, acids on, 347 
basic dyes on, 98, 119, 137, 138, 
348, 354, 355 
composition, 37, 45, 112 
cross-section, 54, 69 
dyeing at the boil, 349 
identification, 71, 76, 77, 84, 85, 


86 
size, 434, 435 
Celanthrene dyes, application meth- 
ods, 308 
composition, 308 
on acetate silk, 308, 368 
Celascour, composition and use, 130 
in dyeing, 139, 288, 289, 379, 386, 
427 
Celatene dyes, application methods, 
298, 300, 301, 408 
composition, 113, 114, 121, 278, 
aA Bes 275, OU0, 308, 321, 322, 
on acetate silk, 284, 300 to 303 
on wool, 334 
Celfect yarn, 426 
Set dyes, application methods, 
on acetate silk, 307 
Cellit color formulas, 248 
Cellit dyes, application methods, 
181, 203, 248, 249, 360 
ee reset 114 166, 180, 188, 
6 


on acetate silk, 123, 180, 248, 249 
Cellite, 67 
Celloxan, 144, 145, 146, 148, 150 
Cellulose acetate crystals, 38, 66, 


formula, 24 

history, 18 

impurities, 38 
precipitation, 27 
preparation, 18, 23, 27, 31 


457 


primary, 19, 26, 30, 32, 33, 37, 44, 
66,. 725.105, T1G6.2112, Aro, 2251, 
PAW ELEY 

purification, 23, 38 

secondary, 19, 26, 28, 33, 37, 44, 66, 
Ve MUS UG ld 2g 

solubility, 27, 28, 30, 33, 34, 36, 37, 
chk TA! 

yield, 31 

Cellulose benzoate, 35 

butyrate, 35 

decomposition, 32, 34 

dextrin, 34 

diacetate, 23, 25, 30, 32, 45, 68, 69 

esters, unsaturated, 32 

hydrate, 25 

monoacetate, 25 

nitrate, see Nitro silk 

polymerisation, 38 

sulfoacetate, 31, 32, 34, 36 

thiourethane, 47 

triacetate=2o, 244 307) olF G2, 800, 
40, 44, 45, 64, 67, 68, 69, 138, 
253 

xanthate, 100 

Cellutyl dyes, application methods, 
li/77370,2 370 

See 160; 71:76, 5266.4-.570, 
3 

on. acetate silk, 123, 176, 177, 359 

Celta silk, see Viscose silk 

Celvis yarn, 426 

Cerium salts (catalyst), 36 

Chardonnet silk, see Nitro silk 

Cheese dyeing, 288, 366, 426 

Chemical theory of dyeing, 107, 108, 
1005-124; “187,156, 2121 5322/9) 
28t>-310, 31S 

Chloramine dyes, 395 to 401 

Chlorantine dyes, 102, 395 to 400 

Chlorates as protective agents, 350 

in dyeing, 149, 227, 228, 229 

Chlorazol dyestuffs, 263, 286, 317, 
351, 359, 378, 396 to 400, 403, 
419 

Chlorides as protective agents, 136, 
350, 362, 373, 439 

in dyeing, 139, 143, 147, 150, 160, 
163, 170, 177, 181, 185, 204, 210, 
212.6221, 227,270 .d0t. cone 

in relustering, 443 

in the saponification of acetate 
silk, 259, 260, 261 

with the dispersol type dyes, 287, 
29 


Chlorinated wool, 49 


458 


Chlorine (catalyst), 29, 35 
in bleaching, 131 
oxyacids in dyeing, 148 
Chloroacetic acid as catalyst, 35 
Chlorobenzene in dyeing, 326 
Chloroform as solvent, 19, 24, 26, 
De 520 i331 e 32, aor ot mi 
25/349 
in anlaysis, 257 
in dry cleaning, 445 
in manufacture, 26, 30 
in printing, 345 
Chlorophenol in dyeing, 326 
PEK alum as a protective agent, 
dyes, see Mordant dyes 
Chromic acid reagent, 73 
Chromium salts (catalyst), 35, 61 
in oxidized blacks, 226, 228, 229 
on acetate silk, 61, 120, 154, 163, 
167, 175, 177, 183, 417 
with nitroso dyes, 217 
ee dyes, application methods, 


on acetate silk, 307 
Cibanone dyes, 320, 369 
Ciba vat dyes on acetate silk, 205, 
206, 207, 208, 209, 365 
“Cire” finish, 438, 440 
Classification of dyestuffs, 166, 184 
Clay in the saponification of ace- 
tate silk, 260 
Clearing acetate silk, 424 
cotton and older rayons, 423 to 425 
unions, 423 to 425 
Cobalt salts (catalyst), 35 
on acetate silk, 217 
Collodion silk, see Nitro silk 
Colloidal dyestuffs for acetate silk, 
see Dispersol type dyes 
solubilization, see Dispersol type 
of dyes 
Colophony in sizing, 436 
Colored acetate silk, manufacture 
of, 23. 41.42, 106 
Color fastness on acetate silk (also 
see Fastness), 108, 123, 124, 140 
rivering or veining, 431 
Compound shades on acetate silk, 
291, 306 
Condensing agents, 34 
Cone dyeing, 426 
Congo Red test for mercerization, 
94, 97 
Coomassie dyes, 151, 174, 175, 410, 
411, 414, 419 


ACETATE SiUg 


Cop dyeing, 366 


Copper as catalyst in dyestuff man- 


ufacture, 188, 314 

in cuprammonium silk, 82 

in dyeing acetate silk, 153, 154, 
217, 227, 228, 229, 288, 386, 427 

glycerol reagent, 78 

oxide reagent, 72 

salts as protective agents, 350 

salts on acetate silk, 62, 153 

Cotton-acetate silk unions, acid 

dyes on, 183, 358 to 360, 421 

Azonine Direct dyes on, 391 

basic dyes on, 138, 353 to 357, 359 

Caledon dyes on, 365 to 368, 390 

Celanthrene dyes on, 391 

Celatene dyes on, 383, 390 

Cellit dyes on, 181, 360, 421, 424 

Cellutyl dyes on, 376, 378 

clearing, 423 to 425 

developed dyes on, 214, 231, 236, 
a 241, 243, 244, 375 to oie 

direct cotton dyes on, 204, 236, 
274, 318, 338, 341, 347, 349, 350, 
ee to 357, 359, 380, 392 to 403, 
1 

discharges on, 342, 343, 344 

Dispersol dyes on, 391 

dispersol type dyes on, 316, 317, 
oa 324, 331, 376, 377, 379 to 
91 

Duranol dyes on, 391 

dyeing by the saponification proc- 
ess, 262 

Extra Pastes on, 391 

finishing, 437, 442 

Ionamines on, 268, 377 

mercerizing, 56, 57, 58 

mordant dyes on, 182, 183, 339, 
358 to 360 

printing, 339, 340, 341, 345 

scouring, 129, 130, 131 

Setacyl Direct dyes on, 179, 359 

S.R.A. dyes on, 280, 284, 369, 371 
377, 386 

sulfur dyes on, 160, 361 to 363, 
424 

vat Fe on, 160, 364 to 374, 379, 
39 


Cotton identification, 74, 86 
linters, 23 
properties. 53, 64 
CR dyes, 392 to 403, 410 to 414 
Creases in fabrics, 431. 437 
Creatine as assistant, 148 


= eo ee A 


Eee 


en 
- 


: 


SUBJECT INDEX AB 


Crepe effects, 56, 439, 440 
finish, 439 
Cresols in acetate silk, 45 
in dry cleaning, 38 
in dyeing, 326 
Cresolsulfonic acid, 363, 373 
Crinkling effect, see Crepe effects 
Crocking of developed colors, 228 
of Ionamines, 267 
of dispersol type colors, 284, 287, 
299, 301, 302, 305, 309 
of vat colors, 206, 369 
Cross-dyeing, fastness to (also see 
Fastness), 138, 158, 181, 236, 
284, 287, 302, 347, 359, 361, 364, 
368, 370, 379, 407 
Cross-section of acetate silk, 40, 59, 
54, 57, 69 
of Celanese, 54, 69 
of cuprammonium silk, 59, 60, 69 
of DuPont silk, 63 
of Industrial fiber, 65 
of Lustron, 50. 69 
of nitro silk, 61, 69 
of Rhodiaseta, 57 | 
of true silk, 68, 69 
of Tubize silk, 61 
of viscose silk, 63, 65, 67, 69 
Cuprammonium reagent on saponi- 
fied acetate silk, 257 
Cuprammonium silk, basic dyes on, 
98, 101, 112 
cross-section, 59, 60, 69 
direct cotton dyes on, 99, 101 
dyeing, 98, 102 
identification, 71, 74, 77, 79, 80, 
81, 82, 83, 84, 86, 87 
properties, 44, 46, 49, 52, 53, 55, 
ce 59, 60, 64, 65, 66, 69, 98, 101, 


sulfur dyes on, 101 
vat dyes on, 101, 103 
Cuprammonium solution on acetate 
silk, 257, 345 
Cyclohexanone as solvent, 38 
in relustering, 443, 444 


Dammar resin in sizing, 435, 436 


- Deacetylation of acetate silk, see 


Saponification and Hydrolysis 
Decahydronaphthalene as_ dispers- 
ing agent. 284, 326 
“as as dispersing agent, 284, 


Degumming true silk, 64, 126, 134, 
135, 349 
Dehydrating agents (catalyst), 34 
Sane finish (see Blinding), 439, 
Denier of acetate silk, 61 
Desizing acetate silk, 126 to 136, 436 
Desmotropism, 124 
Determination of sulfates in cellu- 
lose acetate, 36 
Developed colors, application 
methods, 225, 226, 232 to 250, 
305, 316, 318, 390 
ue two-bath method, 216, 222, 
on acetate silk, 45, 108, 115, 121, 
124215 ts 250.7, 200; e207, 8 20U, 
200505 B07, 370% tO ss mOuG, 
399, 400 
Developing colors on ‘rayons, 103, 
3/7540 3/7 
the Ionamines, 270 
Development of rayon, 17 
Dextrin in finishing, 440 
in printing. 346 
in sizing, 434, 435 
Diacetone alcohol as solvent, 38 
Diamine Blue test for merceriza- 
tion, 97 
dyes, 118, 161, 286, 317, 395 to 403 
Diamineral dyes, 402. 403 
Diaminogene dyes, 403 
Dianil dyes, 397 to 401 
Dianol dyes, 152, 395 to 400 
Diastofor in desizing, 128 
in the dye bath, 139 
Diazine dyes, 395 to 400 
Diazo dyes, 103, 181, 395 to 400 
Diazogene dyes, 394 
Diazo Solamine dyestuffs, compo- 
sition. 215, 283 
Solamines on acetate silk, 249, 375 
Diazotizing bases on acetate silk 
(see Developed colors), 45, 
124, 213 to 250, 270, 427 
TIonamines, 270 
Dichlorethylene as solvent, 42 
Dichlorohydrin as solvent, 38 
in dyestuff manufacture, 199 
Diethyl phthalate in finishing, 441 
Differences and variations in ace- 
tate silk, 23, 27. 71, 83, LiSe123; 
126, 137, 169, 393, 394, 411, 428, 
429 : 
Dimethyl sulfate (catalyst), 35 


9 


460 


pce: reagent, 76, 78, 80, 
6 


Diphenyl black on acetate silk, 216, 
dyes, 409 
‘ Diphenylmethane dyes on acetate 
silk, 140, 157, 315 
Direct colors with developed color 
components, 217, 236, 237, 238, 
239, 242, 248 
cotton dye printing formulas, 337 
Direct cotton dyes by the dispersol 
method, 284 
ee acetate silk white, 392 to 
0 
on acetate silk, 111, 120, 121, 151, 
152, 160, 161, 166, 171, 203, 204, 
256, 299, 338, 376, 392 to 403, 
418, 429 
on acetate silk, application meth- 
oats 151, 152, 161, 287, 355, 392, 
9 
on rayons, 98, 392 to 403 
Discharge effects on dyed acetate 
silk, 169, 177, 179, 181, 338 to 
346 
printing formulas, 343 
Discharging Dispersol Yellow, 343 
the acid and mordant colors on 
acetate silk, 169, 177, 179, 344 
the Acridine colors, 342 
the Acronol colors, 342, 343 
the basic colors, 342 
the Cellit colors, 181 
the Cellutyl colors, 177, 342, 343 
pe eeket cotton colors, 342, 344, 
the Duranol colors, 342 
the Ionamine colors, 343 
the Setacyl Direct colors, 179 
Dispersing agents, 280, 282, 290, 
298, 307, 309, 314, 315, 317, 318, 
319, 323, 325, 328, 331, 333, 407 
Dispersol dyeing theory, 110, 111, 
119, 122, 124, 156, 166, 278 to 
284 
(brand) dyes on acetate silk, 299, 
300, 323, 408 
type colors, stripping, 424, 425 
Dispersol type dyes, application 
methods, 172, 184, 203, 205, 227, 
rie 380, 383, 384, 390, 391, 408, 
composition, 110, 119, 121, 166, 
168,184" 192.7195," 203, 205. 211, 
214, 278 to 284, 298, 312 to 336 


ACETATE SILK 


development of the, 265, 278 to 
284, 298 
dispersion of the (also see Dis- 
persing agents), 108, 156, 227, 
298, 328 
on acetate silk, 123, 124, 169, 242, 
a to 336, 361, 364, 379 to 391, 
2 
on cellulose fibers, 335, 379 
on silk, 334 
see S.R.A., Celatene, Duranol, 
Dispersol, Direct, Azonine, Ci- 
bacete, Celanthrene, and Cella- 
cete dyestuffs 
Disulfine dyes, 411, 414, 419 
Dopes, 20 
Drum dyeing, 386, 427 
Dry cleaning acetate silk, 38, 444, 445 
dyeing, 114, 115 
Drying acetate silk, 437 
machines, 437 
Dry spinning, 39, 40, 70, 436 
Dull finish, see Deluster 
Du Pont silk, cross section, 63 
see Viscose silk 
Duranol dyes, application methods, 
299, 408, 419 
composition, 121, 278, 282, 298, 
299, 312 -Ad3,1 820 
on acetate silk, 284, 299 
Duranthrene dyes, 369, 371 
Durindone dyes on acetate silk, 
205, 209 
DuVivier silk, see Nitro silk 
Dee by precipitation, 156 to 162, 


faults and troubles, 128, 138, 139, 
169, 204, 214, 269, 289, 291, 292, 
347, 428 to 431 

hypotheses (acetate silk), 104 to 
125, 264 

machines, 288, 426, 427 

older rayons, see Nitro, Viscose, 
and Cuprammonium silks 

properties of acetate silk, 36, ral 
104 to 125, 137, 404, 411, 429 

properties of rayons, 46, 98 

unions (see Cotton, Silk, Wool), 
347 

rivering or veining, 431 

Dyestuff agglomeration in the fiber, 
116, 117, 281, 288 
fixation on acetate silk, 112, 138 
impurities, 120, 204, 350, 351 


nates Tans taal 


SUBJECT INDEX 461 


orientation, 116, 147, 222, 281 
solubilization, 110, 167, 264, 278, 
279, 281 
Dyestuffs, substantive affinity for 
acetate silk, 281 


“Egg-shell” finish, see Deluster 
finish 
Elasticity of acetate silk, 53, 56, 
428, 432 
of rayon, 49, 53, 54, 56 
Electrical resistance of acetate 
silk, 64 
Electrolysis of acetate silk, 114 
Electrophoresis of acetate silk, 114 
ecole test for identification, 


aoe of acetate silk, 53, 55, 
of rayon, 49, 53, 54, 55, 56 


Embossing acetate silk materials, 
441, 442 

Enzyme resistance of acetate silk, 
64 


steep in desizing, 127 
Epichlorohydrin as dispersing 
agent, 284, 314 
as solvent, 38 
eat manufacture, 199, 284, 
in printing, 345 
Eridan dyes, 368 
Erie dyes. 395 to 400 
Esparto, 335 
Ether in dyeing acetate silk, 252 
Ethyl acetate as solvent, 28, 38 
dyeing, 107, 108, 110, 113, 114, 115 
in dry cleaning, 38 
Ethylcellulose, dyeing, 277 
Ethylene chlorohydrin as dispers- 
ing agent, 284, 314 
in dyestuff manufacture, 199 to 
202, 284, 314 
in printing, 338, 339 
Ethyleneglycol in printing, 338, 339 
en tetrachloride as solvent, 
er ccelycel in printing, 
“Extra Pastes for Acetate Silk,” 
application methods, 306, 391 
composition, 113, 186, 306 
mate Pastes” on acetate silk, 306, 


Fast Bases, application methods, 
218 


composition of the, 219 
on acetate silk, 218 
Fastness of colors on acetate silk, 
increasing the, 153, 286, 310, 
SL 
of ae on acetate silk, 337, 340, 
4s 


of the Acedronole colors, 236 

of the Acetate colors, 177 

of the acid colors on acetate silk, 
115, 168, 169, 172, 174, 190, 196, 
202, 416 

of the Azole colors, 244 

of the Azonile colors, 241 

of the Azonine Direct colors, 305 

of the bases on acetate silk, 109 

of the basic colors on acetate 
silk, 137, 138, 144, 153, 154, 168, 
348 

of the Celanthrene colors, 308, 309 

of the Celatene colors, 300, 302, 
303 


of the Cellacete colors, 308 

of the Cellit colors, 181 

of the Cibacete colors, 307 

of the developed colors on acetate 
Silie d2e ee a2 elf eee 
236, 241, 244, 249, 376, 379 

of the Diazo Solamine colors, 
249, 376 

of the direct cotton colors, 395 

of the Dispersol (brand) colors, 
300 


of the dispersol type colors, 312, 
1301191 020,824; OL Osan ora: 
406 to 409 

of the’ Duranol colors, 299 

of the Gallocyanine colors on 
acetate silk, 120, 154, 175, 268, 
359 

of the Ionamine colors, 124, 266, 
267, 208, 2/2, 273 

of the mordant colors on ace- 
tate silk, 120, 154, 168, 169, 174, 
177, 183, 190 


of the Setacyl Brilliant colors, 


of the Setacyl colors, 157, 158 _ 
of the Setacyl Direct colors, 179, 
180 


of the S.R.A. colors, 284, 285, 286, 
287, .290, 371, 372 

of the vat colors on acetate silk, 
205, 211, -364, 372 


462 


-Fast Salts, composition of the, 220 
Fats in sizing, 435, 436 
Feel of acetate silk, 43, 60, 301, 439 
Fehling’s reagent, 79 
Filling materials in finishing, 440 
sizes for, 432 
Films, 30, 72 
Finishing, 58, 432 to 445 
Fixing colors in prints, 337, 339, 
* 340, 341, 343 
Flammability of acetate silk, 64 
Flax, 335 
Flexibility of acetate silk, 47 
Formaldehyde  sulfoxylates, 181, 
342, 343, 424 
treatment, 45 
Formic acid in dyeing, 139, 223, 
232, 242. 270, 2/1, 273, 359, 09%, 
407, 408, 409 
in finishing, 438, 439 
in stripping, 424 
with Ionamines, 270, 271, 273 
Formopon, 342 
Formosul, 340, 343 
Formyl dyes, 414, 415 
Four-color effects, 404, 418, 421 
Frankfurter silk, see Nitro silk, 99 
Fuchsin (decolorized) reagent, 77 


Gallocyanine dyes, application 
methods, 142, 154 
on acetate silk, 142, 154, 358, 359 
Gallopont dyes, 338 
Gasoline in dry cleaning, 445 
Gasproof acetate silk materials, 


Gelatin as a protective colloid, 439 
in dyeing, 147, 159, 160, 161, 205, 
212) 22), 222, 223,224,314 
in finishing, 440 
in saponification, 258 
in sizing, 433 to 435 
silk, 49, 60, 66, 84 
sizing, 74, 127, 128 
Glazed acetate silk, 62, 437, 438, 443 
Glucose in printing, 337 
in saponification, 258 
in sizing, 433 to 435 
in the dye bath, 139, 205, 212, 373 
Glue as a protective agent, 369 
as a resist, 345 
in dyeing, 161, 207, 223, 290, 314, 
317, 325, 363, 369, 370, 390 
in finishing, 439 
in sizing, 74 


ACETATE SILK 


Glycerol as solvent, 28 
esters in dyeing, 253 
ether in dyestuffs, 191 
in dispersol dyes, 284, 314 
in mounting, 85 
in printing, 339, 341 
in the dye bath, 139 
Glyceryl acetate in acetate silk, 149 
Glycidic acids in dyestuffs, 188 
Glycine dyes, 190, 192 
Glycol esters in dyeing, 253 
ether in dyes, 191 
Glycollic acid dyes, 193 
Gotze reagent, 79, 80,. 81 
Guanidine as assistant, 148, 149 
Gum mastic in sizing, 435, 436 
soap in dyeing, 362 
tragacanth in oxidized black ap- 
plication, 228, 229 
tragacanth in finishing, 439 
tragasol in finishing, 440 
tragasol in sizing, 433 to 435 
Gums in dyeing, 325 
Gyco Neutral dyes, 356, 417 


Haematin, 164 ’ 

Haller test for mercerization, 97 

Hand dyeing, 426 

Handling acetate silk, 126, 426, 427, 
428, 432, 444 

ae finish, 438, 440, 441, 

44 

Heat test for identification, 73, 74, 86 
for rayons, 352 

Helindone dyes on acetate silk, 205, 


209 
Hemp, 82, 335 
mercerization test, 94 
Hexahydrobenzene in dyestuffs, 326 
Hexahydrocresol in dyestuffs, 326 
Hexahydrophenol as _ dispersing 
agent, 284 
in dyeing, 326 ' 
in scouring, 130 
Hexalin as dispersing agent, 284 
in dyeing, 326 
in scouring, 130 
History of dyeing acetate silk, 105, 
137, 254, 278 
Hooke’s “Micrographia,” 17 
Hosiery dyeing (see Knit goods), 
214, 231, 290, 351, 375, 376, Sea) 
386, 427 
Humidity conditions during wind- 
ing and weaving, 428, 432 


publECI INDEX 


Hummel’s silk, see Gelatin silk 

Hungarian silk, see Nitro silk 

Hydration, 19, 29 

Hydrobromic acid in. dyeing, 252 

Hydrocarbon oils, dyeing, 108, 167 

Hydrocellulose, 33, 34, 98, 99, 254 

Hydrochloric acid in dyeing ace- 
a Silk, 292, 2/0, 271, 279, 280, 
1 

on acetate silk, 344 
with the Ionamines, 270, 271 

Hydroextracting, 437 

Hydrogen ion concentration in de- 
veloping or coupling, 218 

Hydrolysis of acetate silk (see Sa- 
ponification), 62, 64, 106, 126, 
1 e205. 212, 200, 252, 253, 254, 
256, 349, 362, 428 

in manufacture (also see Ripen- 
ine) Dee 26,029, 32, 33, 


Hydron dyes, 369 
Hydrosulfite in discharging, 343 
in dyeing acetate silk, 204, 205, 
Beeeur e206, 209, -210, 211, 212, 
Ao leoce 
in stripping, 76, 340, 424, 425 
resisting, 341 
Hydroxyl groups in dyestuffs, 116, 
12imiss, 189, 264, 320, 322, 323, 
324, 325 
Hygroscopic properties, see Regain 
Hypochlorite bleaching, 76, 131, 
pee a2 
in printing vat dyes, 339 
in stripping, 425 
Hypochlorites on oxidized blacks, 
226,.22/ 


Identification of the rayons, 71 to 90 
Imino groups in dyestuffs, 116, 192 
Immunized cotton, 335, 336 
Indanthrene dyes, 205, 206, 209, 212, 
320. 368, 369 
Indigoid vat dyes, 205, 315, 339, 369 
Indigo on acetate silk, 160, 210 
Indigisol dyestuffs, 210, 373 
Indophenols on acetate silk, 210, 
grieeet? 2515. 317, 322 


Industrial Fiber silk, cross-section, 


Infusorial earth, 346 

Iodine-sulfuric acid reagent, 83 

Iodine test for mercerization, 91 
test for starch (desizing), 127 


463 


Todine-zine chloride reagent, 83 
Ionamine affinity for cotton or re- 
generated rayon, 267, 378 
Ionamine dyes, application meth- 

ods, 266, 270, 273, 378 
development, 105, 278, 281 
differentiation of, 269 
on acetate silk, 77, 108, 122, 123, 

124, 169; 202, 215, 264. to) 277, 

2/9317. 310s 409 

Ionamine printing formulas, 340 
Ionamines, direct, 267, 268, 271, 

212,203 
on wool, 267 
Oe a of the direct, 109, 124, 


with sodium carbonate, 273, 378 
Irish moss in finishing, 440 

in sizing, 433 to 435 
Ironing acetate silk, 63 
Iron salts on acetate silk, 120, 163, 

167 AAs 4 el fences 

Isobutylated naphthalene, 333 
Isomerpin in dyeing, 139 

in scouring, 130 
Isonitroso groups in dyestuffs, 116 
Isopropylated naphthalene, 333 


Janus dyes, 141, 142, 355 
Jelly glaze in sizing, 434, 435 
Jig dyeing, 288, 300, 361, 427 
Jute, 82, 335 


Kaline dyes, 356, 416 
Kana gum in finishing, 440 
Kapok, 82 
Katanol after-treatment, 144, 153 
as a mordant, 102, 139, 153, 164, 
165, 262 
in union dyeing, 420 to 422 
on acetate silk, 139, 144, 153, 262 
Katigen dyes, 360 
Kerosene as precipitant, 24 
Ketones as solvents, 38 
Ketonic groups in dyestuffs, 121, 167 
K gum in sizing, 433 to 435 
Kier boiling, 127 
Kinkead test for mercerization, 94, 
95, 96 
Kiton dyes, 412, 413 
Knit goods dyeing (see Hosiery), 
300, 385, 427 
finishing, 437, 438 
Knitting, 432 
Kryogene dyes, 362 


464 


Lactic acid as solvent, 346 
in clearing, 354, 423 
in dyeing, 139 
in printing, 346 
treatment of rayon, 45 
Lanacyl dyes, 413, 414 
Lard in sizing, 436 
Lead acetate paper for identifica- 
tion, &l 
Lehner silk, see Nitro silk 
Lemon oil in identification, 85 
Leveling aids in dyeing, 130, 139, 
242, 287, 289, 299, 326, 385, 392, 
393, 427, 428, 429 
properties of dyestuffs, 168, 169, 
206, 214, 266, 269, 270, 288, 299, 
301, 302, 386, 407, 411, 416, 428 
Level shades on saponified acetate 
silk, 254, 260, 262 
Light on acetate silk, 60 
Linen mercerization test, 94 
properties, 51, 74, 82 
Lissamine dyes, 411, 413, 414 
Litmus paper in identification, 74 
Loading materials in finishing, 440 
Lubricant for acetate silk, 432, 436 
Ludigol, 341 
Luna silk, see Viscose silk 
Luster (see Blinding and Deluster), 
9, 43, 56, 57, 60, 62, 63, 64, 73, 
77, 99 100,101, 127, 142, 182 
233, 269, 337, 339, 341, 349, 404, 
408, 439, 440 
loss of in the saponification proc- 
ess, 254, 261, 337 
Lustron, acids on, 347, 408, 438 
basic dyes on, 98, 108, 112, 119, 
137, 138, 140, 143, 256, 348, 353; 
354, 429 
composition, 37, 38, 45, 62, 112 
cross-section, 50, 69 
dispersol dyes on, 284 
hydrolysis of, 256 
identification, 71, 76, 77, 84, 85, 86 
resistance to boiling water, 348, 


354, 408 


Machine dyeing, 288, 385, 426, 427 
Magenta (decolorized) reagent, 77 
Magnesium oleate in sizing, 436 
Magnesium salts (catalyst), 36, 62 
as protective agents, 350, 439 
in dyeing, 120, 143, 147, 148, 151, 
160, 204, 212, 221, 222, 224, 227 


ACETATE SILK 


in the saponification of acetate 
silk, 260, 261 
(catalyst), 23, 36 
Mone of acetate silk, 23, 25, 
Mat finish, see Deluster 
Mechanical or physical finishing 
effects, 440 
theory of dyeing, 107, 279, 308 
Mennell test for mercerization, 96 
Mercerizing cotton-acetate silk 
unions, 56, 57, 58 
Mercerized cotton, detection, 91 
Mercerizing, effect on dyeing prop- 
erties, 56, 57, 
Metachrome dyes, 171 | 
Metallic luster finish, see “Hard 
candy” finish 
Meteor silk, see Nitro silk 
Methylamine sulfate (catalyst), 32, 


33 
Methylene Blue reagent, 76, 77 
test for mercerization, 94 
Methylpyridine as assistant, 148 
Methylxylenesulfonamide in finish- 
ing, 442 
Microbiological injury of acetate 
silk, 43, 64 
Microscopy of the rayons, 44, 46, 
48, 50, 54, 57, 59, 61, 63, 65, 67, 
68, 69, 114, 115, 152 
Millon’s reagent, 76, 77 
Mineral acids in dyeing, 139, 252, 
270, 271, 279, 280, 310, 344, 409, 
416, 417 
Mixed ester fibers, 23, 40 
Mold and mildew resistance of ace- 
tate silk, 43, 64 
Molybdates in dyeing, 160 
Monel metal in dyeing, 386, 427 
Monochlorohydrin as solvent, 38 
in dyestuff manufacture, 199 — 
Monomethylaniline as assistant, 149 
Mordant colors, see Acid colors 
dyes on acetate silk (Also see 
Acid dyes), 121, 142, 160, 163, 
bie! 165, 166 to 202, 343, 358 to 
“Mordant for Acetate Silk” (Bad- 
ische), 165 
Mordanting acetate silk, 113, 120, 
139, 147, 156, 163, 164, 165, 255 
methods of, 147, 163, 164, 165 
rayon, 102 
with acid dyestuffs, 170, 354 
Mordant LB, 258 


SUBJECT INDEX 465 


Naphtha in dry cleaning, 445 
Naphthalene compounds as 
stuff precipitants, 161, 162 
dyes, 414 
Naphthalene-formaldehyde conden- 
sation products, 284, 318, 328 
Naphthalenesulfonic acid as dis- 
eae agents, 318, 319, 331, 


Naphthamine dyes, 394 
Naphthenic acids as 
agents, 319, 333 
in sizing, 435, 436 

Naphthol dyes, 413, 414, 415 
salts as dyestuff precipitants, 160 
paul AS, composition of the, 


dye- 


dispersing 


on acetate silk, 218 
Naphthols, see Developed colors 
2- Naphthol -7-sulfonic acid in 
printing, 162 
erage 30rs° acid (catalyst), 


Naphthylamine Black 4B reagent, 


dyes, 415 
Neolan dyes, 413, 414, 417 
Neptune dyes, 344, 413, 414 
Nekol A, 139 
Newport acid dyes, 411, 412 
direct dyes, 393 to 400 
Niagara dyes, 395 to 400 
Nickel oxide reagent, 78 
Nickel salts (catalyst), 35 
salts on acetate silk, 217 
Niobium salts (catalyst), 36 
Nitrates as protective agents, 350 
in dyeing, 148, 149 
Nitric acid in dyeing, 252 
on acetate silk, 344 
test for identification, 74 
p-Nitroaniline reagent, 78 
Nitrobenzene as solvent, 28, 30, 38 
m-Nitrobenzenesulfonic acid, see 
Ludigol 
Nitrocellulose silk, see Nitro silk 
Nitrogen oxyacids in dyeing, 148 
«Nitro groups in dyestuffs, 110, 113, 
Pict 175, 1160, 189, 196, 197, 
210, 315, 323, 324 
Nitro silk, basic dyes on, 98, 99, 
Piteli2 
cross-section, 69 
developed colors on, 117 
direct cotton dyes on, 99 
dyeing, 98, 102, 110 


identification, 71, 72, 74, 79, 80, 81, 
83, 86 
original undenitrated, 14, 53, 72, 
79, 99, 110 
properties, 44, 46, 49, 52, 53, 55, 
56, 59, 60, 61, 64, 65, 66, 69, 98, 
99, 254, 255, 404 
sulfur dyes on, 99 
vat dyes on, 99, 103 
Nitroso groups in dyestuffs, 116, 
200, 217, 315 
p-Nitrosophenol, desmotropism of, 


Noppen dyes, 400 


Oiling acetate silk, 432 
Oils in sizing, 432, 435, 436 
Oleic acid in acetate silk, 45 
Olive oil emulsion, 432, 438, 439 
in A and finishing, 432, 438, 
44 


Omega-sulfonic acid dyestuffs, see 
Ionamines 

Organic bases as dyestuff precipi- 
tants, 160 

Orientation of the dyestuff in the 
acetate fiber, 116 

Ostwald chromometer, 97 

Oxalates as protective agents, 350 

Oxamine dyes, 344, 401 

Oxazine dyes on acetate silk, 140, 
Z00;-212.°315 

sulfato dyes, 200 

Oxidized blacks on 
Zea\tg. 430 

Oxidizing agents on acetate silk, 
So. 13] 1320153, doe 

Oxyamine dyes, 398, 399, 400 

Oxycellulose, 58, 79, 80, 82, 99, 111 

Oxychrome dyes, 176 

Oxydiamine dyes, 399, 402, 403 

Oxydiaminogene dyes, 402 

Oxydianil dyes, 397 to 400 


acetate silk, 


Padder in dyeing, 361, 375 

Paddle dyeing machine, 427 
Palatine dyes, 414, 415 

Paper pulp, 23 

Para Diamine dyes, 402 

Paraffin, dyeing, 108 

Paramine dyes, 203, 397 to 400, 402 
Para-Red on acetate silk, 216 
Patent, first rayon, 17 


466 


Patents on acetate silk manufac- 
ture, 39, 40, 41, 42 5 
on cellulose acetate, 18, 19, 20, 
25. 26,/27, 28, 29; Sl iaonse 
on colored acetate silk, 41, 42 
on dyeing “assistants,” 147, 148, 
140 7150.15) 0327 
on dyeing by precipitation, 160, 
161, 162 
on finishing, 439 to 443 
on mixed ester fibers, 40, 41 
on printing acetate silk, 162, 197, 
316, 319, 323, 324, 325, 327, 328 
on relustering, 443, 444 
on sizes, 435, 436 
on the acid type dyes, 184 to 202 
on the Celatenes, 312 to 336 
on the Cellit dyes, 180, 188, 196 
on the developed colors, 185, 199, 
191, 194, 220 to 230, 316, 318, 
326, 329 / 
on the direct cotton 
160, 161, 165, 194, 204 
on the dispersol type dyes on ace- 
tate silk, 192, 195, 212, 227, 312 
£0. 00. 
on the dispersol type dyes on 
other fibers, 334 to 336 
on the Ionamines, 185, 187, 224, 
274 to 277 
on the mordant dyes, see Acid 
dyes 
on the oxidized blacks, 225, 226, 
227, 228 
on the saponification process, 257 
to 262 , 
on the Setacyl Brilliant dyes, 157 
on the sulfato dyes, 197 to 202 
on the sulfur dyes, 160, 165, 204 
on the vat dyes, 150, 151, 160, 
DAP 21 Ose 21 Zio Loe 
320; 322 
on thiocyanates in dyeing, 151 
Pattern effects in finishing, 442 
Penetration in dyeing, see Leveling 
Peptonizing agents, 34 
Barge bleaching, 76, 133, 
Permeability of acetate silk, 45, 47 
Peroxide bleaching, 76, 132, 425 
Perspiration on acetate silk, 60 
Phenol after-treatment, 153 
as solvent, 38, 327 
as swelling agent, 327 
in acetate silk, 45 
in dry cleaning, 38, 445 


dyes, 151, 


ACETATE SILK 


in manufacture, 33 

in relustering, 443, 444 

salts as dyestuff precipitants, 160 

sulfurized (see Katanol), 164, 
165, 422 


Phenols in dyeing (see Developed 


colors), 108 
in eon (also see Resorcinol), 


see Developed colors 
phone compounds in finishing, 
groups in dyestuffs, 167 
Phenolsulfonic acid (catalyst), 26 
ees as protective agents, 


3 
in dyeing, 149, 150 
in the saponification of acetate 
silk, 259 
Phosphoric acid (catalyst), 23, 35 
on acetate silk, 344 
Phosphorous oxychloride, 35 
Photomicrograph of Celanese silk, 
44, 46, 54, 69 : 
rah adics silk, 44, 46, 59, 


9 
of DuPont silk, 44, 63 
of Industrial Fiber silk, 44, 65 
of Lustron silk, 44, 50, 69 
of nitro silk, 69 - 
of Rhodiaseta silk, 57 
of true silk, 48, 68, 69 
of Tubize silk, 46, 61 
of viscose silk, 44, 46, 63, 65, 67, 


69 
Phot oe 123, 124, 268, 283, 284, 


Phthalates in mordanting, 164 
Physical theory of dyeing, see Me- 
chanical theory of dyeing 
ed acid test for identification, 


Piece goods dyeing, 288, 366, 427 
Pin dyeing, 288 

Pine oil in dry cleaning, 445 
“Pinking” of acetate silk, 134 
Piperidine as assistant, 148, 149 
Plastifying agents, 24, 26, 42, 45 


-Plutamine dyes, 400 


Pontachrome dyes, 176, 358, 412, 
413, 414 
Pontacyl dyes, 412, 413, 415 
Pontamine dyes, 395 to 401 
Scarlet B reagent, 76, 79 
Porcelain rollers, 288 
Porosity of acetate silk, 45, 47 


SUBJECT INDEX 


Potassium bitartrate in dyeing, 182 
ethyl sulfate in dyeing, 149 
Potassium salts as protective agents, 
136, 350 
in acetate silk, 62 
in relustering, 444 
Pressure dyeing, 426 
Primazine dyes, 413, 415 
Printing acetate silk and unions, 
106, 121, 169, 337 to 346 
saponification process, 106, 121, 
254 to 263, 337 to 346 
Printing acid and mordant dyes on 
acetate silk, 169, 197, 337, 339, 


340 

Azole dyes, 341 

Azonile dyes, 341 

Azonine dyes, 341 

basic dyes on acetate silk, 337, 
338, 339, 340 

Celanthrene dyes on acetate silk, 


Celatene dyes on acetate silk, 341 
developed colors, 340, 341 
Dipheny! Black, 340 
cece cotton dyes on acetate silk, 


dispersol type dyes on acetate 
silk, 339, 341 

Duranol dyes on acetate silk, 299, 
341, 342 

“Extra Pastes”’ 
341 


Ionamine dyes on acetate silk, 


‘on acetate silk, 


Rapid Fast dyes on acetate silk, 
340 

Silkon dyes, 341 

S.R.A. dyes on acetate silk, 339, 
341 

sulfur dyes on acetate silk, 204, 
339 

two-color effects, 341 

ee on acetate silk, 337, 339, 
3 


Properties (general) of acetate silk, 
36, 43 to 70 

Protalin AZ, 76 

Protection in boiling solutions, 135 

Protective colloids in dyeing, 147, 
148, 150, 160, 161, 162, 185, 190, 
196, Blanes, O07 223, 224, 329, 
363, 369, 373 

in finishing, 439 
Protectol, 363, 373 
Pyramidol dyes, 171, 203 


467 


Pyramine dyes, 344, 398, 401, 402 
Pyrazolone dyestuffs, 319 
ere as solvent, 28, 30, 38, 47, 


in dyeing, 148, 149 
in printing, 345 
Pyrogene dyes, 362 
Pyroxylin silk, see Nitro silk 


Quinolin dyes, 413, 414 


Radio dyes, 413, 414, 415 
Raffa, 335 
Ramie, 82, 335 
mercerization test, 94 
Rapidase in desizing, 128 
Rapid Fast dyes, composition of 
the, 220 
on acetate silk, 218 
printing the, 340 
Rayon consumption by the textile 
industries, 16 
history, 17 
Rayon production 
companies, 15, 21 
by countries, 16 
by years, 15 
Rayon properties, 43, 98 
Rayons, detecting, 352 
general dyeing formulas, 102 
Reel dyeing, 427 
Refinishing glazed acetate silk, 443 
Refractive index of acetate silk, 66, 
84, 85 
of rayons, 60, 66, 84, 85 
test for identification, 84, 85 
Regain of acetate silk, 45, 47, 48, 
49, 52, 53, 428 
of rayons, 45, 46, 47, 48, 49, 52, 
54, 56, 432 
Relustering acetate silk, 62, 442 to 


by American 


444 
Reserve salt, 362, 363 
Resins in sizing, 435, 436 
Resin soaps in sizing, 435, 436 
Resisted cotton, see Immunized 
cotton 
Resist printing, 341, 345 
Resorcinol after-treatment, 153 
in discharging, 342 
in dyeing and printing, 144, 338 
Retarding agents in dyeing acetate 
silk, 111, 139, 170, 172 
Rhodes test for identification, 79, 
80, 81 


468 


Rhodiaseta, basic dyes on, 348 
blinding, 43, 62, 77, 126, 135, 348 
cross-section, 
dispersol dyes on, 284 
dyeing, 107, 123, 127; 142, 284 
finishing, 438, 440 
hydrolyzed, 429 
identification, 57, 71 
in wool or silk unions, 408 
Ionamine dyestuffs on, 270 
manufacture, 21, 39 
properties, 43, 53, 62, 65, 71, 107, 

123, 142, 348 
resistance to boiling water, 348, 
349 
scouring, 126, 127, 135, 136 
specific gravity, 6 
staining, 393, 394 
Ripening (see Hydrolysis in manu- 
facture), 23, 27, 28, 31 
Rongalite in printing, 339, 342, 343 
Ruthenium red test for identifica- 
tion, 82, 83 


Salicylates in mordanting, 164 
Salicylic acid as dyestuff precipi- 
tant, 161 
napon cae in finishing, 439, 440, 
of acetate silk, methods of, 257, 
258, 439 
Saponification process, 
weight in the, 254, 255 
of dyeing acetate silk, 106, 121, 
152, 153, 165: 206, 254 to 263 
Saponified acetate silk, 72, 84, 128, 
204, 206, 210, 254 to 263, 347, 
361, 428, 439 
analysis of, 257 
basic dyes on, 255, 256, 262, 429 
direct cotton dyes on, 121, 255, 
256, 429 
mordanting, 255 
printing on, 106, 121, 254 to 263 
properties, 53, 64, 118, 254 to 263, 
428, 439 
sulfur dyes on, 255 
vat dyes on, 255 
Saponin in dyeing, 160, 161 
Schweitzer’s reagent, 72 
Scintillating effects, 40 
Scroop finish, 143, 438, 439 
Scouring acetate silk, 126 to 136, 
254, 431 
unions, 129 


loss of 


ACETATE SILK 


Scouring and bleaching, combina- 
tion process, 132 
ea Brilliant color formulas, 
Setacyl Brilliant dyes, application 
methods, 158 
composition, 156, 157 . 
on ee silk, 123, 156 to 160, 
1 


Setacyl color formulas, 159 
Setacyl Direct dyes, application 
methods, 179, 405 
composition, 168, 179 
on acetate silk, 122, 123, 156, 166, 
179, 180, 203 
eis dyes, application methods, 
1 


on acetate silk, 123, 156 to 162 
Setacyl salt A, 156, 159, 161 
Shading colors, 430 
Shellac as a resist, 345 
Silica gel in the saponification of 

acetate silk, 260 
Silicates in the saponification of 
acetate silk, 259, 260, 262 
Silk, acetate silk dyes on, 404 to 421 
Silk-acetate silk unions, Acetate 
(brand) dyes on, 405 
acid dyes on, 202, 355, 358 to 369, 
404 to 421 

basic dyes on, 355, 404 to 421 

bleaching, 132, 406 

Celanthrene dyes on, 308, 407 

Celatene dyes on, 298, 406 to 409 

Cellit dyes on, 405 

Celluty! dyes on, 405, 409 

clearing, 424, 425 

developed dyes on, 236, 237, 406 

discharges on, 342, 343, 344 

Dispersol (brand) dyes on, 406 

dispersol type dyestuffs on, 298, 

319, 406 to 409 

Duranol dyes on, 298, 406 to 409 

finishing, 442 

Gyco Neutral dyes on, 417 

Ionamines on, 268, 405, 406 

Kaline dyes on, 416 

printed effects, 345 

scouring, 129 

Setacyl Direct dyes on, 405 

S.R.A. dyes on, 406 to 409 

Sulfato dyes on, 202 

union dyes on, 418 
Silk boil-off liquor in dyeing, 139, 

147, 205, 221, 222, 224, 226 

cross-section, 68, 69 


SUBJECT INDEX 469 


degumming, 64, 126, 134, 135, 349 
dyeing, 157, 404 
identification, 71, 73, 74, 77, 78, 
82, 84, 85 
Silkons, application methods, 247, 
248 


composition of the, 247 
Silkon dyes on acetate silk, 215, 
247, 248 
Silk properties, 46, 48, 49, 50, 52, 55, 
56, 60, 64, 65, 66, 68, 77, 108 
S.R.A. dyestuffs on, 282 
with Rhodiaseta, degumming, 
1S Ac ue Be 
Silver nitrate-sodium thiosulfate 
reagent, 79, 80, 81, 87 
tests for identification, 79, 80, 81 
Size application, 436 
preparation, 432 to 435 
retained by skeins, amount of, 
435 
Sizes, grading, 434, 435 
Sizing and finishing, 432 to 445 
experiments, 432 to 435 
Skein dyeing, 288, 426, 427 
sizing, 433, 434, 435 
Slasher sizing, 433 
ee cial wool, see Viscose 
sil 
Soaping after dyeing, 233, 241, 244, 
2802290, 1301, 328, 363, 367, 377, 
406, 419 
Soaps as protective colloids, 439 
in dyeing, 147, 221, 224, 242, 251, 
252, 287, 299, 306, 307, 318, 332, 
409, 421 
in sizing, 435, 436 
in stripping, 423 to 425 
in the saponification of acetate 
silk, 260, 261 
insoluble, in sizing, 435, 436 
Sodium acetate in applying the de- 
veloped colors, 216, 218, 232, 
245, 305 
Sodium bicarbonate in finishing, 
438 


in stripping, 423 

Sodium bisulfate (catalyst), 33 
sodium bisulfite as antichlor, 132 
in dyeing, 362 
in stripping, 425 

Sodium carbonate in dyeing, 289, 

627 330,.077, 3/8, 391 

in stripping, 424 


Sodium chloride in refinishing, 443 
cresolate in dyeing, 368 
o-cresotate in dyeing, 161 
dicresyl phosphate as assistant, 

1502212 
diphenylaminesulfonate as as- 
sistant, 161 
naphtholate in dyeing, 368, 371 
Sodium phenolate in degumming 
silk, 135 
RAM raed 363, 368, 369, 370, 371, 


Sodium resorcinate in dyeing, 368 
Sodium salts (catalyst), 36 
as protective agents, 349, 350, 439 
in acetate silk, 62 
in relustering, 444 
Sodium silicate on acetate silk, 163 
thiosulfate as antichlor, 425 
Soie de France, see Nitro silk 
Solamine dyes, 317 
Soledon dyes, 210, 373 
polubiLy test for identification, 71, 


Solution theory of dyeing, 107, 108, 
110; 111, 113, 114, 156,167, 266, 
281, 292 

Solvents in dyeing acetate silk, 
221, 242, 251 to 253 

secondary, 325, 332 

Solvents in printing, 338, 339, 345, 

346 
in relustering, 443 
in scouring agents, 129, 130 
Specific gravity of acetate silk, 64, 
65, 86, 140 
test for identification, 86 
Specific rotation, 38 
Spinning bath, 23, 39, 45, 70 
solvent, 23, 39 
S.R.A. Blacks, 290, 377, 409 
color formulas, 285, 292 to 297, 
te 373, 380 to 389, 410, 417, 
colors, stripping, 424, 425 
Diazo Solamines, see Diazo Sol- 
amines 

S.R.A. dyes, application methods, 
130, 287, 288, 290, 390, 408 

composition, 113, 278 to 284, 287, 
298, 312 to 336 

development of tthe, 265, 278 to 284 

on acetate silk, 77, 215, 249, 278 
to 297 

Stability of acetate silk, 32, 36, 62, 
120,5,127, 


470 


Staining acetate silk, 110, 203, 204, 
236, 241, 341, 347, 350, 353, 35/7, 
369, 370, 375, 392 to 403 

Staining cotton or older rayons, 
158, 179, 180, 181, 182, 231, 237, 
241, 244, 266, 280, 287, 299, 305, 
306, 307, 308, 316, 318, 324, 347, 
354, 359, 360, 375, 378, 379, 384, 
390, 391 

true silk, 158, 180, 181, 282, 299, 
ee 316, 324, 347, 360, 404 to 

wool, 158, 180, 181, 267, 282, 299, 
308, 316, 324, 347, 357, 358, 360, 
404 to 421 

Stain removal, 445 

Standing dye baths, 243, 309, 363 

Stannates in dyeing, 160, 161 

Stannous chloride resist, 341 

Staple fiber, see Viscose silk 

Starch as a resist, 345 

in dyeing, 160, 205, 212, 223, 325 

in printing, 341 

sizing or finishing, 83, 127, 432 to 
435, 440 

Steaming acetate silk, 61, 63, 337, 
339, 340, 341, 440 | 

Steam as a delustering agent, 440 

Stentering, 437 

Stettiner silk, see Viscose silk 

Sthenose process, 45, 83 

Stiffening materials in finishing, 440 

Stilbene dyes, 397 

Stibinic groups in dyestuffs, 172, 328 

Sticks, dye, 426 

Straw, 335 

Strehlenert silk, see Nitro silk 

Stripping colors, 76, 113, 423 to 425 

Strontium salts as protective 
agents, 350 

Structure of acetate silk, 66 

Substantive dyes, see Direct cotton 
dyes 

Sudan dyes, 108, 215, 282 

Sugar as a protective agent, 440 

Sugars in relustering, 444 

Sulfamic dyestuffs, 190, 194, 196 

Sulfanthrene dyes, 369 

Sulfates as protective agents, 136, 
349, 350, 362, 373, 408, 439 

in cellulose acetate, determina- 
tion of, 36 

in dyeing, 139, 143, 149, 170, 181, 
185, 210, 221, 227, 270, 360, 365, 
392 

in relustering, 444 


ACETATE SILK 


in the saponification of acetate 
silk, 261 
- with the dispersol type dyes, 287, 
300, 308 
Sulfato dyestuffs on acetate silk, 
197 to 202, 266 ; 
groups in dyestuffs, 197 to 202 
Sulfides in the saponification of 
acetate silk, 262 _ 
Sulfide test for identification, 81 
Sulfite cellulose liquor in dyeing, 
150, 329, 361, 363, 373 
Sulfites as protective agents, 350 
Sulfobenzenestearic acid as dis- 
persing agent, 325 
Sulfonaphthalenestearic 
dispersing agent, 325 
Sulfonated castor oil as dispersing 
agent, 282, 284, 298, 317, 319 
Sulfonated oil in dyeing, 147, 182, 
206, 221, 224, 282, 284, 288, 290, 
299, 301, 306, 307, 309, 310, 314, 
315, 317, 318,- 320, 323; 325° ee 
332, 370, 379, 393, 427 
in printing, 341 
in sizing and finishing, 432, 439 
in stripping, 424, 425 


acid as 


Sulfonic acid groups in dyestuffs, 


110, 114; 116,121, 123; 167,163 
171, 172, 188, 189, 193, 195, 196, 
199, 264, 266, 279, 280, 284, 315, 
316, 404 
Sulfophenolstearic acid as dispers- 
ing agent, 325 ; 
Sulforicinoleic acid, see Sulfonated 
castor oil 
Sulfoxite C in printing, 339 
Sulfur chloride (catalyst), 35 
colors, stripping, 424 
dioxide (catalyst), 30 
dye printing formulas, 339 
Sulfur dyes on acetate silk, 121, 204, 
205, 361 
on acetate silk, application meth- 
ods, 160, 204, 361, 362 
on rayons, 99, 103 
Sulfuric acid, see Catalysts, 
formaldehyde test for merceriza- 
tion, 96 
groups in cellulose acetate and 
acetate silk, 32, 36, 62, 111, 112, 
137, 168 
in Oe 252, 270, 271, 409, 416, 


on acetate silk, 344 
test for identification, 81 


ae a ee ee 


ery ee OT 


een se ee ee ee ae ee se 


SUBJECT INDEX 471 


Sulfurized phenols, see Katanol 
Sulfur Khaki Y reagent, 76, 79 
Sulfur oxychloride (catalyst), 35 
en test for identification, 


Supramine dyes, 344, 413, 414 
Swelling agents in dyeing, 106.221, 
Zolator 253 
in printing, 327, 338, 339 
in relustering, 443, 444 
Swelling of acetate ‘silk, 7 VPA 
750100. 118; 251 


Tannates in dyeing, 147, 160, 221 


Tannin on acetate silk, 120, 139, 144, 


P50 900.) 105, 182, 262, 338, 355 
Tartaric acid after-treatment, 245 
in dyeing, 139 
in finishing, 438, 439 
Temperature effects on acetate silk, 
Bion es, 3,74, 126, 127, 205, 
437, 438 
Tensile strength of acetate silk, 
43, 46, 47, 51, 56, 254, 261, 426, 
432, 439 
Pretavonss 4/, 49, 50, 51, 52, 53, 
54, 55, 56, 99 
Tetrachlorethane as solvent, 19, 24, 
Sop le 
in dry cleaning, 445 
in dyeing, 325 
Tetrahydronaphthalene as dispers- 
ing agent (Tetralin), 284, 326 
in dyeing, 113, 242, 284, 326 
in scouring, 130 
Tetralin, see Tetrahydronaphtha- 
lene 
Thianthrene dyes, 367 
Thiazine dyes, 140, 201, 
398, 401 
sulfato dyes, 201 
Thickening agents in printing, 337 
to 346 
Thiocyanates in discharging, 343 
in eon Eytyeloc, 163, 204, 212, 
258, 32 


ESIC AEY 


in mordanting, 164 

in printing, 341 

in relustering, 443, 444 
Thioglycollic acid dyes, 193 
Thioindigo dyes, 205, 331 
Thionol dyes, 263, 340, 362 
Thorium salts (catalyst), 36 
Three-color effects, 348, 356, 404, 

417 to 420 


Tin salts (catalyst), 36 
in dyeing, 120, 147, 163, 164, 165, 
221, 224; 422 
Toluene as ‘solvent, 28 
in dry cleaning, 445 
in sizing, 436 
Dae a on cotton, 
Toluene-p-sulfochloroamide in 
bleaching, 134 
PRS ee eat in finishing, 


Paes SG in finishing, 
1 


Toluidine as solvent, 38 
in acetate silk, 134 
in dyeing, 326 
Toning colors, 430 
Topping colors on acetate silk, 147, 
LOS AS J 1/8 2185225 ed sees, 
262, 289, 430 
Tragacanth in printing, 337, 343 
Triacetin as solvent (also see Ace- 
titi), 38 
in finishing, 441 
in relustering, 443, 444 
Se ada in dry cleaning, 


in dyeing, 325 
Tricresyl phosphate in acetate silk, 
42 
Triphenylmethane dyes, 140, 200, 
4 


sulfato dyes, 200 
Triphenyl phosphate in acetate silk, 
42 


Tube dyeing, 426 
Tubize, silk, cross-section, 61 

see Nitro silk 
Tumeric paper in identification, 74 
Tungstates in dyeing, 160 
Turgoids, 73, 106 
Turkey-red oil, see Sulfonated oil 
Turpentine in dry cleaning, 445 

in sizing, 436 
Twitchell reagent in dyestuffs and 

dyeing 228:7325.5 sol" 333 


Ultraviolet light, 66, 140, 310 
Uneven colors, see Leveling 
Union dyeing, general, 122, 347 to 
352, 353 to 422 
dyes, 358, 402, 403, 418 
Unions, clearing, 423 to 425 
desizing, 127 


472 


scouring, 127, 129, 131 

see Cotton, Wool, Silk 
Uranium salts (catalyst), 36 
Urea, 148 | 


Vanadium salts (catalyst), 35 
on acetate silk, 227 
Vat dye oe formulas, 208, 209, 
372.1500 
printing formulas, 339 
carboxylated, 168 
on acetate silk, 110, 134, 184, 204, 
205.10 1212 
on acetate silk, application meth- 
ods, 152, 160, 206, 209, 210, 251, 
315, 317, 3202 331; 33/2098, 000; 
370, 371 
on cotton, 117, 364 to 374 
on rayon, 98, 99, 103, 364 to 374 
on silk, 364, 369 
on wool, 364, 369, 374 
sulfonated, 168 
Vatting temperature of Caledon vat 
_ dyes, 365 
of Ciba vat dyes, 207 
Viscose silk, basic dyes on, 98, 100 
cross-section, 63, 65, 67, 69 
direct cotton dyes on, 99, 100 
dyeing, 98, 100, 102 
identification, 71, 74, 77, 79, 80, 
81, 82, 83, 84, 86, 87 
properties, 44, 46, 48, 49, 50, 51, 
52, 53, 55, 56, 59, 60, 62, 63, 64, 
65, 66, 69, 98, 100, 255, 404 
sulfur dyes on, 101 
vat dyes on, 100, 101, 103 
Viscose unions, bleaching, 131 
Vistra silk, see Viscose silk 


Warp dyeing, 366 
sizing, 432 
odung acetate silk, 43, 45, 60, 126, 


Water for dyeing, 289, 307, 366 
Waterproof acetate silk material, 
1 


Waterproofing rayon, 45, 46 

Water resistance of acetate silk, 43, 
51, 62, 63, 64, 73, 254, 426, 432 

Waxes in sizing, 435, 436 

Weaving, 432 

Wetting-out acetate silk, 43, 45, 106, 
126, 138, 139, 254, 432 

White acetate silk effects, 347 to 
352, 358, 362, 369, 374, 375, 392 


ACETATE Siti 


to 403, 405, 411 to 417, 418, 420, 
424, 427, 429 
cotton effects, 354, 356, 358, 378, 
379, 391, 404, 423 to 425, 429 
silk effects, 356, 406, 424, 425, 429 
Winch dyeing, 427 
Wool, acetate silk dyes on, 172, 188, 
193, 194, 195, 202, 267, 268, 282, 
322, 334 to 336, 357, 404 to 421 
Wool-acetate silk unions, Acetate 
(brand) dyes on, 359, 405 
acid dyes on, 169, 347, 348, 350, 
357, 358 to 360, 404 to 421 
basic dyes on, 357, 404 to 421 
bleaching, 132 
Celanthrene dyes on, 308, 407 
Celatene dyes on, 298, 406 to 409 
Cellit dyes on, 249, 405, 421 
Cellutyl dyes on, 359, 405, 409 
clearing, 424, 425 
developed dyes on, 236, 237, 406, 
409, 421 
direct cotton dyes on, 402, 421 
discharges on, 342, 343, 344 
Dispersol (brand) dyes on, 406 
to 409 
dispersol type dyestuffs on, 298, 
319, 406 to 409 
Duranol dyes on, 298, 406 to 409 
finishing, 442 
Gyco Neutral dyes on, 417 
Ionamines on, 267, 268, 405, 406 
Kaline dyes on, 416 
printed effects, 345 
Setacyl Direct dyes on, 405, 417 
S.R.A. dyes on, 284, 406 to 409 
Sulfato dyes on, 202 
union dyes on, 402, 418 
vat dyes on, 374 
vor identification, 73, 74, 78, 82, 


Wool-like effects on acetate silk, 
439, 440 

Wool, properties, 49, 50, 51, 52, 53, 
59, 77, 108, 118, 128 


Xanthate silk, see Viscose silk 
X-rays, 66, 68 
Xylene as solvent, 28 

dyes, 413 

in dry cleaning, 445 

in sizing, 436 
Xylenesulfonamide in finishing, 441 
Xylidine as solvent, 38 

in acetate silk, 134 


4, 
7 


n dyeing, 366, 426, 427 


dyes, 400 
ride on acetate silk, 344 


‘2 SUBJECT INDEX 


473 


Zing salis <.catalyst ),- 23,125,429; 30, 
Sams GR. at) 
as protective agents, 350 
salts in dyeing, 120, 139, 147, 148 
LEO SUS ee ler ee4 27: 


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